Soluble MANF in pancreatic beta-cell disorders

ABSTRACT

The invention provides, in part, methods for diagnosing a pancreatic β-cell disorder, predicting a subject&#39;s risk of developing a pancreatic β-cell disorder, monitoring pancreatic β-cell function or pancreatic β-cell mass in a subject at risk of developing a pancreatic β-cell disorder, monitoring efficacy of a treatment of a pancreatic β-cell disorder in a subject, identifying a subject having an increased risk of developing a pancreatic β-cell disorder, selecting a subject for treatment of a pancreatic β-cell disorder, selecting a subject for participation in a clinical study, and detecting endoplasmic reticulum stress in a pancreatic β-cell. These methods include determining at least one level of soluble mesencephalic astrocyte-derived neurotrophic factor (MANF) in a biological sample from the subject. Also provided are pharmaceutical compositions containing a soluble MANF protein and kits containing an antibody or an antigen-binding antibod fragment that binds specifically to a soluble MANF.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application and claims priority to U.S.patent application Ser. No. 14/374,190, filed on Jul. 23, 2014, which isthe national stage application under 35 U.S.C. § 371 of InternationalPatent Application No. PCT/US2013/022768, filed on Jan. 23, 2013, whichclaims priority to U.S. Provisional Patent Application Ser. No.61/590,021, filed on Jan. 24, 2012. Each of these applications arehereby incorporated by reference in their entirety.

BACKGROUND OF THE INVENTION

Loss of the function or number of pancreatic β-cells in a subjectcontributes to the pathogenesis of several diseases, including type 1diabetes (diabetes mellitus), type 2 diabetes, and Wolfram syndrome. Intype 1 diabetes, the patient has high blood glucose levels because ofinsulin deficiency. Generally speaking, absolute deficiency of insulinoccurs in patients with type 1 diabetes, whereas relative deficiency ofinsulin occurs in patients with type 2 diabetes. Increasing evidenceindicates that reduced functional pancreatic β-cell mass is a commonfeature of both type 1 and type 2 diabetes, as well as genetic forms ofdiabetes such as Wolfram syndrome (Pipeleers et al., Novartis FoundSymp. 292:19-24, 2008). During the progression of type 1 or type 2diabetes, pancreatic β-cell function and mass gradually decline,eventually leading to insulin deficiency and hyperglycemia. Recentfindings indicate that “stressed” pancreatic β-cells are susceptible todysfunction and death (Oslowski et al., Curr. Opin. Endocrinol. DiabetesObes. 17:107-112, 2010; Oslowski et al., Curr. Opin. Cell Biol.23:207-215, 2011; Fonseca et al., Trends Endocrinol. Metab. 22:266-274,2011). Diagnostic markers that aid in predicting the susceptibility of asubject to develop pancreatic β-cell dysfunction and death will behelpful for treating or delaying the progression of pancreatic β-celldisorders (e.g., type 1 or type 2 diabetes) in subjects.

SUMMARY OF THE INVENTION

The invention is based, in part, on the discovery that stressedpancreatic β-cells produce and secrete soluble mesencephalicastrocyte-derived neurotrophic factor (MANF), soluble MANF protectspancreatic β-cells from endoplasmic reticulum stress-induced apoptosis,and soluble MANF maintains endoplasmic reticulum redox homeostasis inpancreatic β-cells.

In view of these discoveries, provided herein are methods (e.g., invitro methods) of diagnosing a pancreatic β-cell disorder in a subject,predicting a subject's risk of developing a pancreatic β-cell disorder,monitoring pancreatic β-cell function or pancreatic β-cell mass in asubject (e.g., a subject at risk of developing a pancreatic β-celldisorder), identifying a subject having an increased risk of developinga pancreatic β-cell disorder, selecting a subject for treatment ofpancreatic β-cell disorder, selecting a subject for participation in aclinical study, and detecting endoplasmic reticulum stress in apancreatic β-cell. These methods include determining at least one levelof soluble MANF (e.g., endogenous levels of soluble MANF in a biologicalsample from the subject or in a culture medium).

Also provided herein are methods (e.g., in vitro methods) of diagnosinga pancreatic β-cell disorder in a subject that include determining alevel of soluble mesencephalic astrocyte-derived neurotrophic factor(MANF) in a biological sample from a subject; comparing the level ofsoluble MANF in the biological sample to a reference level of solubleMANF; and identifying a subject having an elevated level of soluble MANFin the biological sample as compared to the reference level as having apancreatic β-cell disorder.

Also provided herein are methods (e.g., in vitro methods) of predictinga subject's risk of developing a pancreatic β-cell disorder thatinclude: determining a level of soluble mesencephalic astrocyte-derivedneurotrophic factor (MANF) in a biological sample from a subject;comparing the level of soluble MANF in the biological sample to areference level of soluble MANF; and identifying a subject having anelevated level of soluble MANF in the biological sample compared to thereference level as having an increased risk of developing a pancreaticβ-cell disorder, or identifying a subject that has a decrease or nosignificant difference in the level of soluble MANF in the biologicalsample as compared to the reference level as having a normal ordecreased risk of developing a pancreatic β-cell disorder.

Also provided herein are methods (e.g., in vitro methods) of monitoringpancreatic β-cell function or pancreatic β-cell mass in a subject thatinclude: determining a level of soluble mesencephalic astrocyte-derivedneurotrophic factor (MANF) in a biological sample from the subject at afirst time point; determining a level of soluble MANF in a biologicalsample from the subject at a second time point; comparing the level ofsoluble MANF in the biological sample at the second time point to thelevel of soluble MANF in the biological sample at the first time point;and identifying a subject having an elevated level of soluble MANF inthe biological sample at the second time point compared to the level ofsoluble MANF in the biological sample at the first time point as havinga decrease in pancreatic β-cell function or a decrease in pancreaticβ-cell, or identifying a subject having a decrease or no significantchange in the level of soluble MANF in the biological sample at thesecond time point compared to the level of soluble MANF in thebiological sample at the first time point as having no change or anincrease in pancreatic β-cell function, or no change or an increase inpancreatic β-cell mass in the subject.

Also provided are methods (e.g., in vitro methods) of monitoring theefficacy of treatment of a pancreatic β-cell disorder in a subject.These methods include determining a level of soluble MANF in abiological sample from the subject at a first time point, determining alevel of soluble MANF in a biological sample from the subject at asecond time point, and comparing the level of soluble MANF in thebiological sample at the second time point to the level of soluble MANFin the biological sample at the first time point, where (i) the firsttime point is prior to treatment and the second time point is any timepoint following the initiation of treatment, or (ii) the first timepoint is following the initiation of treatment and the second time pointis at a later time point during or after treatment; and a decreasedlevel of soluble MANF in the biological sample at the second time pointcompared to the level of soluble MANF in the biological sample at thefirst time point indicates that the treatment was effective in thesubject.

Also provided are methods of treating or delaying the onset of apancreatic β-cell disorder in a subject, methods (e.g., in vitromethods) of reducing endoplasmic reticulum stress in a pancreaticβ-cell, or methods (e.g., in vitro methods) of reducing or delayingendoplasmic reticulum stress-induced apoptotic cell death in apopulation of two or more pancreatic β-cells. These methods include theadministration of an effective amount of a soluble MANF or apomorphineto a subject, or contacting the pancreatic β-cell or the population ofpancreatic β-cells with a soluble MANF or apomorphine. In someembodiments, the soluble MANF contains a sequence that is at least 80%(e.g., 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%)identical to a mammalian soluble MANF protein sequence (e.g., any one ofSEQ ID NOS: 2 and 4-7). In some embodiments, e.g., wherein the methodincludes administering apomorpine, the subject does not have erectiledysfunction or Parkinson's disease.

Also provided herein are methods of methods of using any of the solubleMANF described herein (e.g., a soluble MANF comprising a sequence thatis at least 80% identical to SEQ ID NO: 2) or apomorphine in themanufacture of a medicament for treating or delaying the onset of apancreatic β-cell disorder in a subject. Also provided herein areisolated soluble MANF (e.g., an isolated soluble MANF comprisingcomprising a sequence that is at least 80% identical to SEQ ID NO: 2) orapomorphine for use in treating or delaying the onset of a pancreaticβ-cell disorder in a subject.

Also provided herein are methods (e.g., in vitro methods) of screeningfor a candidate compound useful for treating or delaying the onset of apancreatic β-cell disorder in a subject, methods (e.g., in vitromethods) for decreasing endoplasmic reticulum stress in a pancreaticβ-cell, and methods (e.g., in vitro methods) for reducing or delayingendoplasmic reticulum stress-induced apoptotic cell death in pancreaticβ-cells. These methods include providing a pancreatic β-cell, contactingthe pancreatic β-cell with a candidate compound, determining the levelof soluble MANF produced by the pancreatic β-cell in the presence of thecandidate compound, comparing the level of soluble MANF produced by thepancreatic β-cell to a reference level of soluble MANF, and selecting acompound that is associated with an elevated level of soluble MANF beingproduced by the pancreatic β-cell compared to the reference level as acandidate compound for treating or delaying the onset of a pancreaticβ-cell disorder in a subject. In these methods, an elevated level ofsoluble MANF produced by the pancreatic β-cell compared to the referencelevel indicates that the candidate compound may be useful for treatingor delaying the onset of a pancreatic β-cell disorder in a subject,decreasing endoplasmic reticulum stress in a pancreatic β-cell, orreducing or delaying endoplasmic reticulum stress-induced apoptotic celldeath in pancreatic β-cells.

Also provided are methods (e.g., in vitro methods) of screening for acandidate compound useful for treating or delaying the onset of apancreatic β-cell disorder in a subject, decreasing endoplasmicreticulum stress in a pancreatic β-cell, or reducing or delayingendoplasmic reticulum stress-induced apoptotic cell death in pancreaticβ-cells. These methods include providing a mammalian cell (e.g., apancreatic β-cell) expressing a reporter protein containing a BiP signalsequence, a redox-sensitive fluorescent protein (e.g., a redox-sensitivegreen fluorescent protein), and the amino acid sequence of KDEL;contacting the cell with a test compound; determining the amount ofoxidized reporter protein present in the cell; and comparing the amountof oxidized reporter protein present in the cell to a reference level;where an elevated level of oxidized reporter protein in the cellcompared to the reference level indicates that the candidate compoundmay be useful for treating or delaying the onset of a pancreatic β-celldisorder in a subject. In some embodiments, the reference level is theamount of oxidized reporter protein present in a mammalian cell in theabsence of the candidate agent. In some embodiments, the reference levelis a threshold level of oxidized reporter protein.

Also provided are methods (e.g., in vitro methods) of screening for acandidate compound useful for treating or delaying the onset of apancreatic β-cell disorder in a subject, decreasing endoplasmicreticulum stress in a pancreatic β-cell, or reducing or delayingendoplasmic reticulum stress-induced apoptotic cell death in pancreaticβ-cells. These methods include providing a mammalian cell (e.g., apancreatic β-cell) expressing a reporter protein containing a BiP signalsequence, a redox-sensitive fluorescent protein (e.g., a greenfluorescent protein), and the amino acid sequence of KDEL; contactingthe cell with a test compound; determining the amount of reducedreporter protein present in the cell; and comparing the amount ofreduced reporter protein present in the cell to a reference level; wherea decreased level of reduced reporter protein in the cell compared tothe reference level indicates that the candidate compound may be usefulfor treating or delaying the onset of a pancreatic β-cell disorder in asubject. In some embodiments, the reference level is the amount ofreduced reporter protein present in a mammalian cell in the absence ofthe candidate agent. In some embodiments, the reference level is athreshold level of reduced reporter protein.

Also provided are kits including an antibody or antigen-binding antibodyfragment that binds specifically to a soluble MANF (e.g., a humansoluble MANF), and at least one antibody or antigen-binding antibodyfragment that binds to a protein selected from insulin, C-protein, andislet amyloid polypeptide (IAPP). Also provided are pharmaceuticalcompositions that contain a soluble MANF protein (e.g., a soluble MANFprotein containing a sequence at least 80% identical to SEQ ID NO: 2)and/or apomorphine, and at least one additional agent for treating apancreatic β-cell disorder (e.g., pioglitazone, TUDCA, GLP-1, or a DPP-4inhibitor (e.g., sitagliptin, vildagliptin, saxagliptin, linagliptin,dutogliptin, gemigliptin, and alogliptin)).

By the term “pancreatic β-cell disorder” is meant a disease thatincludes, as part of its pathogenesis, a decrease in pancreatic β-cellfunction (e.g., insulin secretion) or a decrease in the number of viableinsulin-secreting pancreatic β-cells present in a subject (pancreaticβ-cell mass). In some embodiments, a pancreatic β-cell disorder can befurther characterized by an increase in the endoplasmic reticulum stressin a population of pancreatic β-cells (e.g., two or more pancreaticβ-cells) in the subject. As described herein a decrease in pancreaticβ-cell function, a decrease in the number of viable pancreatic β-cells(pancreatic β-cell mass), or an increase in the endoplasmic reticulumstress in pancreatic β-cells present in a subject can be detectedindirectly using the methods described herein or other methods known inthe art. Non-limiting examples of pancreatic β-cell disorders includetype 1 diabetes (diabetes mellitus), type 2 diabetes, and Wolframsyndrome.

By the term “pancreatic β-cell function” is meant a biological activitythat is used to describe a mammalian (e.g., human) pancreatic β-cell(e.g., an activity that is specifically unique to a pancreatic β-cell).Non-limiting examples of pancreatic β-cell function include thesynthesis and secretion of insulin, the synthesis and secretion of isletamyloid polypeptide (IAPP), and the synthesis and section of C-peptide.Methods for detecting the synthesis and secretion of insulin, IAPP, andC-peptide are known in the art. Pancreatic β-cell function can also bedetected indirectly using the methods described herein, as well asmethods known in the art (e.g., determining blood glucose levels anddetermining glycated hemoglobin A1C levels).

By the term “pancreatic β-cell mass” is meant the total number of viableinsulin-secreting pancreatic β-cells in a mammal (e.g., a human).Methods for indirectly determining the pancreatic β-cell mass in asubject are described herein. Additional methods for indirectlydetermining the pancreatic β-cell mass in a subject are known in the art(e.g., determining blood glucose levels and determining glycatedhemoglobin A1C levels).

The pancreatic β-cell mass may represent the total number of endogenousviable pancreatic β-cells in a subject or may represent the sum of thenumber of endogenous viable pancreatic β-cells in a subject plus thenumber of viable pancreatic β-cells transplanted into the subject (e.g.,autograft, homograft, or xenografted viable pancreatic β-cells).

By the term “soluble MANF” is meant a protein containing a sequence thatis at least 80% identical to a sequence of a soluble mammalian form ofmesencephalic astrocyte-derived neutrophic factor (MANF). For example, asoluble MANF can be protein containing a sequence that is at least 80%identical (e.g., at least 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%,90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical) toany one of SEQ ID NOS: 2 and 4-7, i.e., to the full length of SEQ IDNOs: 2 or 4-7. In some embodiments, a soluble MANF can be a wildtypemammalian soluble MANF (e.g., SEQ ID NO: 2 and 4-7).

A soluble MANF protein can be administered as a therapeutic treatment(e.g., as a recombinant or purified endogenous protein using any of themethods described herein). A purified soluble MANF protein can be, e.g.,at least 80% (e.g., at least 85%, 90%, 95%, or 99%) pure by dry weight.Additional modified forms of soluble MANF are described herein.

By the term “increase” or “elevated” is meant an observable, detectable,or significant increase in a level as compared to a reference level or alevel measured at an earlier or later time point in the same subject(e.g., in a biological sample from the same subject).

By the term “decrease” is meant an observable, detectable, orsignificant decrease in a level as compared to a reference level or alevel measured at an earlier or later time point in the same subject(e.g., in a biological sample from the same subject).

By the phrase “a compound that is associated with an elevated level ofsoluble MANF” is meant a compound that induces or results in an elevatedlevel of soluble MANF (e.g., protein or mRNA) present, produced by, orsecreted by a mammalian cell that is contacted with the compound, ascompared to the level of soluble MANF (e.g., protein or mRNA) present,produced by, or secreted by a control mammalian cell (e.g., the same orthe same type of mammalian cell) in the absence of the compound.

By the phrase “risk of developing disease” is meant the relativeprobability that a subject will develop a pancreatic β-cell disorder inthe future as compared to a control subject or population (e.g., ahealthy subject or population, or a subject or population with no familyhistory of a pancreatic β-cell disorder). Provided herein are methodsfor determining a subject's risk of developing a pancreatic β-celldisorder (in the future) that include determining a level of solubleMANF.

The term “treating” includes reducing the number of symptoms or reducingthe severity, duration, or frequency of one or more symptoms of disease(e.g., a pancreatic β-cell disorder) in a subject. The term treating canalso include reducing the risk of developing a pancreatic β-celldisorder in a subject (in the future) or delaying the onset of one ormore symptoms of a pancreatic β-cell disorder in a subject.

By the phrase “delaying the onset of a pancreatic β-cell disorder” ismeant an increase in the length of time before one or more symptoms of apancreatic β-cell disorder are observed in a subject. In someembodiments, the subject can be previously identified as having anincreased risk of developing a pancreatic β-cell disorder. As describedherein, a subject can be identified as having an increased risk ofdeveloping a pancreatic β-cell disorder using the methods describedherein or by the observation of a family history of a pancreatic β-celldisorder (e.g., type 2 diabetes).

The term “biological sample” includes any sample collected from asubject that includes a biological fluid. In non-limiting samples, thebiological sample can include blood, serum, plasma, urine, cerebrospinalfluid, saliva, bile, gastric juice, or breast milk.

By the phrase “endoplasmic reticulum stress” is meant an imbalance theendoplasmic reticulum between the production of reactive oxygen species(pro-oxidant species) and the cell's or cellular organelle's ability todetoxify (remove) the reactive oxygen species (or their intermediates)that results in a shift in the redox potential of the lumen of theendoplasmic reticulum and/or an accumulation of misfolded or unfoldedproteins within the lumen of the endoplasmic reticulum. Endoplasmicreticulum stress triggers a unique stress pathway termed the unfoldedprotein response (UPR) (further described herein).

Endoplasmic reticulum stress in a pancreatic β-cell can be caused by anumber of molecular events (e.g., an increased level of free fatty acidsin the endoplasmic reticulum, hyperinsulemia, hyper-production of VEGF,hypoxia, glucose deprivation, mutant islet amyloid polypeptide, mutantinsulin, increased levels of IL-1, increased levels of IFN-γ, or virusinfection). A variety of different chemical agents can also be used toinduce endoplasmic reticulum stress (e.g., thapsigargin or tunicamycin).Endoplasmic reticulum stress has been shown to shift the endoplasmicreticulum from an oxidizing environment towards a more reducingenvironment. In some embodiments, agents that have the ability to shiftthe endoplasmic reticulum from a reducing toward an oxidizingenvironment under ER stress conditions will help reduce ER stress and/ormay reduce or prevent ER stress-induced apoptotic cell death.

Endoplasmic reticulum stress can be detected using a variety ofdifferent methods known in the art. Exemplary methods for detecting,reducing, or delaying the onset of endoplasmic reticulum stress inpancreatic β-cells are described herein.

By the phrase “population of pancreatic β-cells” is meant two or morepancreatic β-cells. In some embodiments, a population of pancreaticβ-cells may be present in a mammalian (e.g., human) subject (e.g., asubject's endogenous pancreatic β-cells, an autograft, homograft, orxenograft of pancreatic β-cells). In some embodiments, a population ofpancreatic β-cells can be cultured in vitro (tissue culture). In someembodiments, a population of pancreatic β-cells is pancreatic β-cellline (e.g., those pancreatic β-cell lines described herein). In someembodiments, a pancreatic β-cell can be derived from any mammalianspecies (e.g., human, monkey (e.g., chimpanzee), mouse, pig, rat, orape). In some embodiments, a pancreatic β-cell population can be aprimary cell line or an immortalized cell line.

By the term “pancreatic β-cell” is meant an insulin-producing cell thatis normally present in the pancreas of a mammal in the islet ofLangerhans. As used herein, the term pancreatic β-cell encompasses apancreatic β-cell present in the body of a mammal (e.g., endogenouspancreatic β-cells, or autograft, homograft, or xenograft pancreaticβ-cells) or a pancreatic β-cell cultured in vitro (e.g., an ex vivo(e.g., primary) culture of pancreatic β-cells from any mammalian speciesdescribed herein or a pancreatic β-cell line (e.g., a primary orimmortalized cell line). In some embodiments, the pancreatic β-cellpresent in a mammal is present in the pancreas. In some embodiments, thepancreatic β-cell present in a mammal is located in a tissue other thanthe pancreas (e.g., in liver tissue). In other embodiments, thepancreatic β-cell is encapsulated in a device (e.g., a biocompatiblepolymer) that is implanted in the subject. The term pancreatic β-cellalso encompasses a pancreatic β-cell in a mammalian (e.g., human, pig,rat, and mouse) cell line or a primary mammalian (e.g., human, pig, rat,and mouse) cell culture. In some embodiments, the pancreatic β-cell canbe genetically manipulated using molecular biology techniques to expressone or more recombinant proteins (e.g., an insulin) and/or decrease theexpression of one or more endogenous proteins.

By the term “endoplasmic reticulum-induced apoptotic cell death” ismeant programmed cell death that is triggered by stress in theendoplasmic reticulum of a cell (e.g., a pancreatic β-cell). In someembodiments, the endoplasmic reticulum stress that induces apoptoticcell death induces the unfolded protein response (UPR) pathway in thecell (e.g., a pancreatic β-cell). Exemplary components of the UPRpathway are described herein. As described herein, endoplasmic reticulumstress can be caused by a number of agents (e.g., biological andchemical agents). Methods for detecting, measuring, decreasing, anddelaying the onset of endoplasmic reticulum-induced apoptotic cell deathin pancreatic β-cells are described herein. Additional methods fordetecting and measuring endoplasmic reticulum-induced apoptotic celldeath are known in the art.

By the term “determining a level” is meant the use of one or morescientific techniques (e.g., molecular biology, molecular genetics,immunological, and biochemical methods or assays) to assess the level ofa particular molecule (e.g., in a biological sample or cell culturemedium). The phrase determining a level includes the physical contactingof one or more reagents that specifically bind to a particular molecule(e.g., an antibody or antigen-binding fragment of an antibody) to asample (e.g., a biological sample or cell culture medium).

By the term “second time point” generally means any point in time thatoccurs after a first time point (e.g., time of admission). A second timepoint can occur, e.g., at least 6 hours, 12 hours, 24 hours, 1 day, 2days, 3 days, 4 days, 5 days, 6 days, 1 week, 2 weeks, 3 weeks, 4 weeks,6 weeks, 2 months, 6 months, 1 year, or 2 years after the first timepoint. In some embodiments, a subject can be administered a treatmentbetween the first time point and the second time point.

By the term “redox-sensitive fluorescent protein” is a protein thatchanges its fluorescence properties (e.g., change in excitation and/oremission spectrum (e.g., peak excitation or emission wavelengths) upon achange in its redox environment (e.g., a change in the redox environmentof the endoplasmic reticulum). In some embodiments, this change in thefluorescence properties of the protein can occur, e.g., as a result ofthe formation and/or breakage of one or more disulfide bonds.Non-limiting examples of redox-sensitive fluorescent proteins includeredox-oxidation sensitive green fluorescent protein (roGFP) andredox-sensitive yellow fluorescent protein (rxYFP). Additionalredox-sensitive fluorescent proteins are known in the art.

Other definitions appear in context throughout this disclosure. Unlessotherwise defined, all technical and scientific terms used herein havethe same meaning as commonly understood by one of ordinary skill in theart to which this invention belongs. Methods and materials are describedherein for use in the present invention; other, suitable methods andmaterials known in the art can also be used. The materials, methods, andexamples are illustrative only and not intended to be limiting. Allpublications, patent applications, patents, sequences, database entries,and other references mentioned herein are incorporated by reference intheir entirety. In case of conflict, the present specification,including definitions, will control.

Other features and advantages of the invention will be apparent from thefollowing detailed description and figures, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an immunoblot showing the levels of MANF protein inconcentrated medium from a culture of a rat pancreatic β-cell line(INS-1 832/13) or in lysate from the rat pancreatic β-cell line (INS-1832/13) after no treatment or treatment with thapsigargin (50 nM) ortunicamycin (0.5 μg/mL) for 24 hours.

FIG. 2 is a graph showing the relative expression of MANF mRNA in a ratpancreatic β-cell line (INS-1 832/13) cultured under the followingconditions: 11 mM glucose (24 hours); 25 mM glucose (24 hours); 25 mMglucose (48 hours); 25 mM glucose (72 hours); 11 mM glucose and 5 μMtunicamycin (TM) (24 hours); or 11 mM glucose and 20 nM thapsigargin(Tg) (24 hours). The data shown were generated using quantitativereal-time PCR (n=3, S.D.).

FIG. 3 is a graph showing the relative expression of MANF, WFS1, TXNIP,and CHOP mRNA in mouse primary islets cultured five days with 5 mMglucose (LG), 11 mM glucose (MG), or 25 mM glucose (HG), or five dayswith 5 mM glucose (LG) and 6 hours with 0.5 μM thapsigargin (TG). Thedata shown were generated using quantitative real-time PCR (n=3; S.D.).

FIG. 4 is a graph showing the relative expression of MANF mRNA in humanprimary islets from two human donors (HP11139-01 and HI 11-20) following24-hour treatment with 5.5 mM glucose (UT), 25 mM glucose (HG), 0.25 μMthapsigargin (TG), 10 μM islet amyloid polypeptide (IAPP), or 500 μMpalmitate with bovine serum albumin (Palmitate). The data shown weregenerated using quantitative real-time PCR (n=3; S.D.).

FIG. 5 is an immunoblot showing the level of soluble MANF in the mediumof human primary islets following no additional treatment or treatmentwith 25 mM glucose (24 hours), 0.25 μM thapsigargin (24 hours), or 0.5mM palmitate (24 hours).

FIG. 6 is an immunoblot showing the level of soluble MANFimmunoprecipitated from the medium of human primary islets following noadditional treatment or treatment with 25 mM glucose (24 hours), 0.25 μMthapsigargin (24 hours), or 0.5 mM palmitate (24 hours). In thisexperiment, human MANF was immunoprecipitated using a rabbit anti-humanMANF antibody (Proteintech), and the same antibody was used to developthe immunoblot.

FIG. 7 is a graph showing the relative expression of BiP mRNA in amurine pancreatic β-cell line (MIN6) transfected with a negative controlsiRNA (NC) or one of three different siRNA molecules targeting MANF mRNA(siMANF #1, siMANF #2, or siMANF #3) following no treatment or treatmentwith 2 μM tunicamycin for 24 hours. These data were generated usingquantitative real-time PCR (n=3; S.D.).

FIG. 8 is an immunoblot showing the levels of cleaved caspase-3 in amurine pancreatic β-cell line (MIN6) untreated or treated for 24-hourswith 1 μM tunicamycin or 100 nM thapsigargin, and further treated with0, 40, or 200 nM soluble MANF.

FIG. 9A is a diagram of Mammalian Endoplasmic Reticulum-LocalizedRedOx-Sensitive GFP (MEROS-GFP).

FIG. 9B is two confocal images of COS7 cells. The fluorescence ofMEROS-GFP is shown in the left panel and the fluorescence of DsRed-ERtracker is shown in the right panel.

FIG. 10A is a set of excitation spectra of MEROS-GFP following notreatment or treatment with DTT at different concentrations (emissionwavelength of 510 nm).

FIG. 10B is an emission spectrum of oxidized MEROS-GFP in untreatedNSC34 cells (excitation wavelength of 394 nm).

FIG. 10C is an emission spectrum of reduced MEROS-GFP in NSC34 cellstreated with 2 mM DTT (excitation wavelength of 473 nm).

FIG. 11 is a set of four confocal microscopy images of MEROS-GFPgathered using a 476-nm excitation wavelength (bottom two panels) or a405-nm excitation wavelength (top two panels) in INS-1 832/13 cellstreated with (right two panels) or without (left two panels) 2 mM DTT.

FIG. 12 is a graph of the MEROS-GFP ratio in INS-1 832/13 cells leftuntreated (no label), or treated with H₂O₂ (1 or 0.1 mM H₂O₂) or DTT(0.1, 0.2, 0.5, 1, 2, 5, or 10 mM DTT). The MEROS-GFP ratio wasdetermined using a plate reader. The data shown are mean±S.D. (n=3).

FIG. 13 is photograph of non-reducing polyacrylamide gel electrophoresis(PAGE) of 4-acetamido-4′-maleimidylstilbene-2, 2′-disulfonic acid(AMS)-modified MEROS-GFP in lysate from cells left untreated (left lane)or treated with 2 mM DTT (right lane). The lysates were either leftuntreated (−βME) (top) or were treated with β-mercaptoethanol (+βME)(bottom) prior to electrophoresis.

FIG. 14 is a graph showing a time course of the MEROS-GFP ratio in NSC34cells that are treated with 1 mM DTT for 10 minutes, and then washed.The MEROS-GFP ratio was calculated at each minute interval between oneminute prior to treatment to four minutes after the wash. The bottomline represents the fluorescence observed with excitation at 473 nm, theblack line represents the MEROS-GFP ratio, and the light grey linerepresents the fluorescence with excitation at 394 nm (n=3; S.D.).

FIG. 15 is fluorescence-assisted cell sorting (FACS) data of INS-1832/13 cells stably-transfected with MEROS-GFP following no treatment ortreatment with DTT (0.2, 0.5, or 10 mM DTT). The data was collectedusing excitation wavelengths of 488 nm and 405 nm, and an emissionspectrum of 510 nm. Going from bottom to top, the different sets of dataare untreated, 0.2 mM DTT, 0.5 mM DTT, and 10 mM DTT (indicating a shiftto a more reduced state following treatment with increasingconcentrations of DTT).

FIG. 16 is a histogram of FACS data of INS-1 832/13 cellsstably-transfected with MEROS-GFP following no treatment or treatmentwith DTT (0.2 mM, 0.5 mM, or 10 mM DTT). The horizontal axis representsthe MEROS-GFP ratio and the vertical axis represents the number ofcells. The peaks from left to right represent cells left untreated, 0.2mM DTT-treated, 0.5 mM DTT-treated, and 10 mM DTT-treated.

FIG. 17 is a graph of the median MEROS-GFP ratio in INS-1 832/13 cellsstably-transfected with MEROS-GFP following no treatment or treatmentwith DTT (0.2, 0.5, or 10 mM DTT). The MEROS-GFP values shown arenormalized to the untreated values.

FIG. 18 is two graphs showing data from FACS analysis of INS-1 832/13cells stably-transfected with MEROS-GFP following no treatment ortreatment with 1 mM H₂O₂ for 30 minutes. The right graph is a histogramof the MEROS-GFP ratio in INS-1 832/13 cells not treated or treated with1 mM H202. The left graph shows the median MEROS-GFP ratio in INS-1832/13 cells not treated (left) or treated with 1 mM H₂O₂ for 30minutes.

FIG. 19 is a graph of the median MEROS-GFP ratio calculated in INS-1832/13 cells using FACS analysis following no treatment or treatmentwith tunicamycin (TM) (5 μM; 24 hours), thapsigargin (TG) (10 nM; 24hours), TG (1 μM; 4 hours), brefeldin A (BreA) (100 ng/mL; 24 hours), orMG132 (100 nm; 24 hours). The error bars represent ±S.D. (*p<0.01). Thedata are normalized to the median MEROS-GFP ratio calculated for theuntreated cells.

FIG. 20 is a histogram showing the MEROS-GFP ratio in INS-1 832/13 cellsleft untreated or treated with 1 μM thapsigargin (TG) for 4 hours.

FIG. 21 is a graph of the median MEROS-GFP ratio calculated in INS-1832/13 cells using FACS analysis following treatment with 11 mM glucose(24 hours) or 25 mM glucose for 24, 48, or 72 hours. The error barsrepresent ±S.D. The data are normalized to the median MEROS-GFP ratiocalculated for the cells treated with 11 mM glucose for 24 hours.

FIG. 22 is a graph of the median MEROS-GFP ratio calculated in INS-1832/13 cells using FACS analysis following no treatment, serumdepletion, or glucose depletion. The error bars represent ±S.D.(*p<0.01). The data are normalized to the median MEROS-GFP ratiocalculated for the untreated cells.

FIG. 23 is a graph of the median MEROS-GFP ratio in INS-1 832/13 cellsleft untreated or treatment with palmitic acid (0.2 mM; 24 hours),palmitic acid (0.2 mM) and high glucose (25 mM) (24 hours), palmiticacid (0.5 mM; 24 hours), oleic acid (0.5 mM; 24 hours), or linoleic acid(0.5 mM; 24 hours). The error bars represent ±S.D. The data arenormalized to the median MEROS-GFP ratio calculated for the untreatedcells.

FIG. 24 is a graph of the median MEROS-GFP ratio in INS-1 832/13 cellsleft untreated or treatment with human islet amyloid polypeptide (IAPP)(10 μM; 24 hours), mouse IAPP (10 μM; 24 hours), or cytokines(interleukin-10 (5 ng/mL), INFγ (100 ng/mL), and TNFα (25 ng/mL); 24hours)). The error bars represent ±S.D. The data are normalized to themedian MEROS-GFP ratio calculated for the untreated cells.

FIG. 25 is two graphs of FACS data from INS-1 832/13 cells leftuntreated (left) or treated with 0.5 mM palmitate (PA) for 24 hours. They-axis represents fluorescence following excitation using 488 nm and thex-axis represents fluorescence following excitation using 405 nm.

FIG. 26 is a graph showing the MEROS-GFP ratio calculated using FACSanalysis in INS-1 832/13 cells following no treatment or treatment with0.5 mM palmitate (PA) or 0.5 mM oleic acid (OA) for 24 hours. The datafor cells treated with palmitate is shifted to the right.

FIG. 27 is a graph showing the percentage of reduced cells in apopulation of INS-1 832/13 cells following treatment with 11 mM glucosefor 24 hours or 25 mM glucose for 24, 48, or 72 hours. The error barsindicate ±standard deviation (**p<0.01).

FIG. 28 is a graph showing the percentage of reduced cells in apopulation of INS-1 832/13 cells following no treatment, serum depletionfor 24 hours, or glucose depletion for 24 hours. The error bars indicate±standard deviation (**p<0.01).

FIG. 29 is a graph showing the percentage of reduced cells in apopulation of INS-1 832/13 cells following no treatment or treatmentwith 10 μM human IAPP, 10 μM mouse IAPP, or a combination ofinterleukin-10 (5 ng/mL), IFNγ (100 ng/mL), and TNFα (25 ng/mL) for 24hours. The error bars indicate ±standard deviation (**p<0.01).

FIG. 30 is a graph showing the percentage of reduced cells in apopulation of INS-1 832/13 cells following no treatment or treatment for24 hours with 0.2 mM palmitate, 0,2 mM palmitate and 25 mM glucose, 0.5mM palmitate, 0.5 mM oleic acid, 0.5 mM linoleic acid, bovine serumalbumin and 0.5 mM palmitate, 0.5 mM palmitate and 0.5 mM oleic acid,and 0.5 mM palmitate and 0.5 mM linoleic acid. The error bars indicate±standard deviation (**p<0.01).

FIG. 31 is a diagram of cells transfected with BiP-P-mCherry and adiagram showing the configuration of flow cytometer laser lines andfilters.

FIG. 32 is a graph of the median BiP-P-mCherry expression in oxidized orreduced INS-1 832/13 cells. The cells were either left untreated or weretreated for 24 hours with 10 nM thapsigargin, 5 μM tunicamycin, 25 mMglucose, serum deprivation, glucose deprivation, 0.5 mM palmitate, 10 04human IAPP, or a combination of interleukin-10 (5 ng/mL), IFNγ (100ng/mL), and TNFα (25 ng/mL). The BiP-P-mCherry expression was determinedusing FACS analysis. The error bars indicate ±standard deviation.

FIG. 33 is two histograms showing oxidized and reduced INS-1 832/13cells treated with 5 μM tunicamycin (TM, upper histogram) or glucosedeprivation (lower histogram) for 24 hours. The x-axis indicates theexpression level of mCherry driven by human BiP promoter.

FIG. 34 is a histogram of the FACS data from INS-1 832/13 cells treatedwith 0.5 mM of palmitate for 24 hours.

FIG. 35 is histogram showing the purity of FACS-separated oxidized andreduced INS-1 832/13 cells.

FIG. 36 is two graphs showing the expression levels of BiP (left graph)and spliced XBP1 (sXBP) (right graph) in INS-1 832/13 cells treated with0.5 mM palmitate for 24 hours. The expression levels of BiP and sXBPwere measured using real-time PCR. The error bars indicate ±standarddeviation.

FIG. 37 is a table showing the expression levels of Derlin3, BiP, Herp,and PDla5 in endoplasmic reticulum purified from oxidized or reducedINS-1 832/13 cells. The expression data was gathered using DNAmicroarray analysis.

FIG. 38 is two graphs showing the percentage of dead cells (left graph)or the median MEROS-GFP ratio (right graph) of INS-1 832/13 cellstreated with DMSO alone, 10 nM thapsigargin (Tg), 10 nM Tg and 10 μMpioglitazone, or 10 nM Tg and 500 μg/mL tauroursodeoxycholic acid(TUDCA).

FIG. 39 is a diagram showing the screening system that uses theMEROS-GFP system.

FIG. 40 are two histograms showing the FACS data gathered from INS-1832/13-MEROS-GFP cells following treatment with 0.5 mM palmitate in theabsence (top left graph) or presence (top right graph) of 10 μMapomorphine (Apo), and a graph showing the percentage of reduced cellsin INS-1 832/13 MEROS-GFP cells following no treatment, or treatmentwith 0.5 mM palmitate in the absence or presence of 10 μM apomorphine.The error bars indicate ±standard deviation.

FIG. 41 is a histogram of FACS data gathered from INS-1 832/13-MEROS-GFPcells stained with Mitoprobe dye after treatment with 0.5 mM palmitate(PA) in combination with or without 10 nM or 50 nM apomorphine (Apo).

FIG. 42 is two graphs showing the percentage of low Awm cells (leftgraph) and percentage of dead cells (right graph) fractionated by FACSanalysis following no treatment or treatment with 0.5 mM palmitate aloneor 0.5 mM palmitate and 10 nM apomorphine.

FIG. 43 is a graph of the percentage of dead cells following notreatment or treatment with 10 nM thapsigargin (Tg) or treatment with 10nM Tg and 10 nM apomorphine.

FIG. 44 are two immunoblots showing the amount of cleaved caspase 3(c-caspase3) and cleaved PARP (c-PARP) present in 10 nMthapsigargin-treated primary human islets (right immunoblot) and 2 μMdoxycycline-treated WFS1 knockdown INS-1 832/13 cells (shWFS1) (leftimmunoblot) treated with 10 nM apomorphine or 10 μM pioglitazone.

FIG. 45 is a graph of fluorescence-assisted cell sorting data showingthe percentage of INS1 832/13 cells (pancreatic (3 cell line) containingthe reduced form of EroGFP in the endoplasmic reticulum followingculture in 11 mM glucose or 25 mM glucose (24 hours) (top panels andbottom panels, respectively), and treatment with 0 or 0.5 μg/mL solubleMANF for 48 hours (left panels and right panels, respectively). Thecells were excited using a wavelength at 473 nm and an emission spectrumof 510 nm.

DETAILED DESCRIPTION OF THE INVENTION

The invention is based, at least in part, on the discovery that solubleMANF is secreted by stressed pancreatic β-cells, and that soluble MANFdelays endoplasmic reticulum stress-induced pancreatic β-cell apoptoticcell death and reduces fluctuation in the redox state of the endoplasmicreticulum in pancreatic β-cells exposed to agents or conditions thatinduce endoplasmic reticulum stress. In view of these discoveries,methods for diagnosing a pancreatic β-cell disorder, predicting asubject's risk of developing a pancreatic β-cell disorder, monitoringpancreatic β-cell function and pancreatic β-cell mass in a subject(e.g., a subject at risk of developing a pancreatic β-cell disorder),monitoring the efficacy of treatment of a pancreatic β-cell disorder ina subject, identifying a subject having an increased risk of developinga pancreatic β-cell disorder, selecting a subject for treatment ofpancreatic β-cell disorder, selecting a subject for participation in aclinical study, and detecting endoplasmic reticulum stress in apancreatic β-cell are provided. These methods include determining atleast one level of soluble MANF (e.g., in a biological sample from thesubject or in a culture medium).

Methods of treating or delaying the onset of a pancreatic β-celldisorder in a subject, reducing endoplasmic reticulum stress in apancreatic β-cell, and reducing or delaying endoplasmic reticulumstress-induced apoptotic cell death in a population of two or morepancreatic β-cells are also provided. These methods include theadministration of an effective amount of a soluble MANF or apomorphineto a subject, or contacting a pancreatic β-cell or a population ofpancreatic β-cells with a soluble MANF. In some embodiments, e.g.,wherein the method includes administering apomorpine, the subject doesnot have erectile dysfunction or Parkinson's disease.

Also provided are methods of screening for a candidate compound usefulfor treating or delaying the onset of a pancreatic β-cell disorder in asubject, decreasing endoplasmic reticulum stress in a pancreatic β-cell,or reducing or delaying endoplasmic reticulum stress-induced apoptoticcell death in pancreatic β-cells. In some embodiments, these methodsinclude providing a pancreatic β-cell, contacting the pancreatic β-cellwith a candidate compound, determining the level of soluble MANFproduced by the pancreatic β-cell in the presence of the candidatecompound, and comparing the level of soluble MANF produced by thepancreatic β-cell to a reference level of soluble MANF. In someembodiments, these methods include providing a mammalian cell (e.g., apancreatic β-cell) expressing a reporter protein containing a BiP signalsequence, a redox-sensitive fluorescent protein (e.g., a redox-sensitivegreen fluorescent protein or redox-sensitive yellow fluorescentprotein), and the amino acid sequence of KDEL; contacting the cell witha test compound; determining the amount of oxidized reporter proteinpresent in the cell; and comparing the amount of oxidized reporterprotein present in the cell to a reference level; where an elevatedlevel of oxidized reporter protein in the cell compared to the referencelevel indicates that the candidate compound may be useful for treatingor delaying the onset of a pancreatic β-cell disorder in a subject,decreasing endoplasmic reticulum stress in a pancreatic β-cell, and/orreducing or delaying endoplasmic reticulum stress-induced apoptotic celldeath in pancreatic β-cells. In some embodiments, these methods includeproviding a mammalian cell (e.g., a pancreatic β-cell) expressing areporter protein containing a BiP signal sequence, a redox-sensitivefluorescent protein (e.g., a redox-sensitive green fluorescent proteinor redox-sensitive yellow fluorescent protein), and the amino acidsequence of KDEL; contacting the cell with a test compound; determiningthe amount of reduced reporter protein present in the cell; andcomparing the amount of reduced reporter protein present in the cell toa reference level; where a decreased level of reduced reporter proteinin the cell compared to the reference level indicates that the candidatecompound may be useful for treating or delaying the onset of apancreatic β-cell disorder in a subject, decreasing endoplasmicreticulum stress in a pancreatic β-cell, and/or reducing or delayingendoplasmic reticulum stress-induced apoptotic cell death in pancreaticβ-cells.

Pancreatic β-Cell Disorders

Pancreatic β-cell disorders are a class of diseases that arecharacterized by a progressive decrease in pancreatic β-cell dysfunctionor pancreatic β-cell mass in the subject. Pancreatic β-cell functionsthat can be decreased in a subject having a pancreatic β-cell disorderinclude, without limitation, insulin production and secretion, C-peptideproduction and secretion, and islet amyloid polypeptide (IAPP)production and secretion. Non-limiting examples of pancreatic β-celldisorders include type 1 diabetes (diabetes mellitus), type 2 diabetes,and Wolfram syndrome. Pancreatic β-cell disorders can occur in humans atany age, e.g., in infants, children, adults, and elderly subjects. Forexample, a pancreatic β-cell disorder can occur in a subject having anage of greater than 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, or 90.

A health care professional (e.g., a physician, nurse, physician'sassistant, nurse's assistant, or laboratory technician) may diagnose asubject as having a pancreatic β-cell disorder by the assessment of oneor more (e.g., two, three, four, or five) symptoms of a pancreaticβ-cell disorder in the subject. Non-limiting symptoms of a pancreaticβ-cell disorder in a subject include a significant increase in bloodglucose levels (e.g., fasting blood glucose levels) compared to ahealthy individual or population (e.g., a fasting blood glucose level ofgreater than 100 mg/dL or greater than 120 mg/dL), a significantincrease in glycated hemoglobin levels (hemoglobin Al C level) comparedto a healthy individual or population (e.g., a hemoglobin A1C levelgreater than 6.5%, greater than 7.0%, or greater than 8.0%), increasedthirst, frequent urination, extreme hunger, unexplained weight loss,presence of ketones in the urine, fatigue, blurred vision, slow-healingsores, mild high blood pressure, and frequent infections. A health careprofessional may also base a diagnosis, in part, on the subject's familyhistory of a pancreatic β-cell disorder. A health care professional maydiagnose a subject as having a pancreatic β-cell disorder uponpresentation of a subject to a health care facility (e.g., a clinic or ahospital). In some instances, a health care professional may diagnose asubject as having a pancreatic β-cell disorder while the subject isadmitted in an assisted care facility. Typically, a physician diagnosesa pancreatic β-cell disorder in a subject after the observation ordetection of one or more symptoms in the subject.

A health care professional may also identify a subject as having anincreased risk of developing a pancreatic β-cell disorder based on oneof more of the following factors: increased weight (e.g., a body massindex of >25 or >30), inactivity, family history of a pancreatic β-celldisorder, race, age, diagnosis with polycystic ovary syndrome, highblood pressure, decreased high-density lipoprotein levels (e.g., below35 mg/dL), and high levels of triglycerides (e.g., above 250 mg/dL).

Provided herein are additional methods for diagnosing a pancreaticβ-cell disorder in a subject (e.g., a subject presenting with one ormore symptoms of a pancreatic β-cell disorder or a subject notpresenting with a symptom of a pancreatic β-cell disorder (e.g., anundiagnosed and/or asymptomatic subject). Also provided are additionalmethods of identifying a subject having an increased risk of developinga pancreatic β-cell disorder. Also provided herein are methods oftreating a pancreatic β-cell disorder in a subject.

Mesencephalic Astrocyte-Derived Neurotrophic Factor (MANF)

An endogenous level of soluble MANF protein, as described herein, can bedetected in any of the methods described herein, e.g., as a marker fordiagnosing a pancreatic β-cell disorder, predicting a subject's risk ofdeveloping a pancreatic β-cell disorder, monitoring pancreatic β-cellfunction and pancreatic β-cell mass in a subject (e.g., a subject atrisk of developing a pancreatic β-cell disorder), identifying a subjecthaving an increased risk of developing a pancreatic β-cell disorder,selecting a subject for treatment of pancreatic β-cell disorder,selecting a subject for participation in a clinical study, and detectingendoplasmic reticulum stress in a pancreatic β-cell. A purified,isolated, and/or recombinant soluble MANF protein can also be used inmethods of treating or delaying the onset of a pancreatic β-celldisorder in a subject, reducing endoplasmic reticulum stress in apancreatic β-cell, and reducing or delaying endoplasmic reticulumstress-induced apoptotic cell death in a population of two or morepancreatic β-cells.

MANF protein is translated as a precursor protein that is subsequentlycleaved and released as a soluble protein from a cell (e.g., apancreatic β-cell). The full-length (precursor) human MANF protein andthe human soluble MANF protein are shown below. The 25-amino acid signalsequence in the precursor human MANF protein is underlined below. Alsoshown below is the mRNA encoding the human precursor MANF protein.

Human precursor MANF Protein  (SEQ ID NO: 1) MRRMWATQGLAVALALSVLPGSRALRPGDCEVCISYLGRFYQDLKDRDVTFSPATIENELIKFCREARGKENRLCYYIGATDDAATKIINEVSKPLAHHIPVEKICEKLKKKDSQICELKYDKQIDLSTVDLKKLRVKELKKILDDWGETCKGCAEKSDYIRKINELMPKYAPKAASARTDL Human soluble MANF Protein(SEQ ID NO: 2) LRPGDCEVCISYLGRFYQDLKDRDVTFSPATIENELIKFCREARGKENRLCYYIGATDDAATKIINEVSKPLAHHIPVEKICEKLKKKDSQICELKYDKQIDLSTVDLKKLRVKELKKILDDWGETCKGCAEKSDYIRKINELMPKYAPK AASARTDLHuman MANF mRNA (SEQ ID NO: 3)ggaggcggtg cggcgcggcg ggtgcggttc agtcggtcggcggcggcagc ggaggaggag gaggaggagg aggaggaggaggatgaggag gatgtgggcc acgcaggggc tggcggtggcgctggctctg agcgtgctgc cgggcagccg ggcgctgcggccgggcgact gcgaagtttg tatttcttat ctgggaagattttaccagga cctcaaagac agagatgtca cattctcaccagccactatt gaaaacgaac ttataaagtt ctgccgggaagcaagaggca aagagaatcg gttgtgctac tatatcggggccacagatga tgcagccacc aaaatcatca atgaggtatcaaagcctctg gcccaccaca tccctgtgga gaagatctgtgagaagctta agaagaagga cagccagata tgtgagcttaagtatgacaa gcagatcgac ctgagcacag tggacctgaagaagctccga gttaaagagc tgaagaagat tctggatgactggggggaga catgcaaagg ctgtgcagaa aagtctgactacatccggaa gataaatgaa ctgatgccta aatatgcccccaaggcagcc agtgcacgga ccgatttgta gtctgctcaatctctgttgc acctgagggg gaaaaaacag ttcaactgcttactcccaaa acagcctttt tgtaatttat tttttaagtgggctcctgac aatactgtat cagatgtgaa gcctggagctttcctgatga tgctggccct acagtacccc catgaggggattcccttcct tctgttgctg gtgtactcta ggacttcaaagtgtgtctgg gattttttta ttaaagaaaa aaaatttctagctgtccttg cagaattata gtgaatacca aaatggggttttgccccagg aggctcctaa aaaaaaaaaa aaaaaaaaaa aaaaaaaaa

Cow, rat, mouse, pig, fly, and zebrafish soluble MANF protein sequenceshave also been described, and are shown below.

Cow soluble MANF (SEQ ID NO: 4)LRQGDCEVCISYLGRFYQDLKDRDVTFSPASIEKELIKFCREARGKENRLCYYIGATEDAATKIINEVSKPLSHHIPVEKICEKLKKKDSQICELKYDKQIDLSTVDLKKLRVKELKKILDDWGETCKGCAEKSDYIRKINELMPKYAPK AASSRTDLRat soluble MANF (SEQ ID NO: 5)LRPGDCEVCISYLGRFYQDLKDRDVTFSPATIEEELIKFCREARGKENRLCYYIGATDDAATKIINEVSKPLAHHIPVEKICEKLKKKDSQICELKYGEC D Mouse soluble MANF(SEQ ID NO: 6) LRPGDCEVCISYLGRFYQDLKDRDVTFSPATIEEELIKFCREARGKENRLCYYIGATDDAATKIINEVSKPLAHHIPVEKICEKLKKKDSQICELKYDKQIDLSTVDLKKLRVKELKKILDDWGEMCKGCAEKSDYIRKINELMPKYAPK AASARTDLPig soluble MANF (SEQ ID NO: 7)LRPGDCEVCISYLGRFYQDLKDRDVTFSPASIEKELTKFCREARGKENRLCYYIGATDDAATKIINEVSKPLAHHIPVEKICEKLKKKDSQICELKYDKQIDLSTVDLKKLRVKELKKILDDWGETCKGCAEKSDYIRKINELMPKYAPK AASSRTDDrosophila melanogaster soluble MANF (SEQ ID NO: 8)LKEEDCEVCVKTVRRFADSLDDSTKKDYKQIETAFKKFCKAQKNKEHRFCYYLGGLEESATGILNELSKPLSWSMPAEKICEKLKKKDAQICDLRYEKQIDLNSVDLKKLKVRDLKKILNDWDESCDGCLEKGDFIKRIEELKPKYSRSE LZebrafish soluble MANF (SEQ ID NO: 9)LKDGECEVCVGFLQRLYQTIQENNVKFDSDSIEKALLKSCKDAKGKENRFCYYIGATSDAATKITNEVSKPMSYHVPVEKICEKLKKKDSQICELKYDKQVDLSSVDLKKLKVKDLKKILEEWGESCKGCVEKSDFIRKINELMPKYAPS AAKARTDL

Mammalian soluble MANF proteins are highly conserved, with human and cowsoluble MANF proteins having 96% identity, human and mouse soluble MANFproteins having 99% identity, and human and pig soluble MANF proteinshaving 97% identity. Human soluble MANF protein also shares 72% identityand 88% similarity with zebrafish soluble MANF protein.

Diagnostic Methods

Provided herein are methods of diagnosing a pancreatic β-cell disorderin a subject. These methods include determining (assaying) a level ofsoluble MANF in a biological sample from a subject, and comparing thelevel of soluble MANF in the biological sample to a reference level ofsoluble MANF. In these methods, an elevated level of soluble MANF in thebiological sample as compared to the reference level of soluble MANFindicates that the subject has a pancreatic β-cell disorder, and adecrease or no significant change in the level of soluble MANF in thebiological sample as compared to the reference level of soluble MANFindicates that the subject does not have a pancreatic β-cell disorder.

As referred to anywhere herein, a “reference level of soluble MANF” canbe a threshold level of soluble MANF, a level of soluble MANF present ina control subject or population (e.g., a subject or population that isnot diagnosed as having a disease (a healthy subject or population),does not have one or more symptoms of a pancreatic β-cell disorder,and/or does not have a family history of a pancreatic β-cell disorder),or a level of soluble MANF in the same subject at an earlier time point.

The levels of soluble MANF can be determined using methods known in theart. For example, the levels of soluble MANF can be detected using anumber of techniques known in the art that utilize antibodies thatspecifically bind to a soluble MANF (e.g., enzyme-linked immunosorbentassay). A number of antibodies that specifically bind to human solubleMANF are commercially available (e.g., rabbit anti-human soluble MANFantibodies available from Sigma-Aldrich and Proteintech).

Any of the methods described herein may further include obtaining orcollecting a sample from a subject (e.g., a biological sample containinga biological fluid, e.g., urine, blood, plasma, serum, or cerebrospinalfluid). In any of the methods described herein, the biological samplecan be stored for a period of time (e.g., at least one hour or at least24 hours) before a level of soluble MANF is determined (e.g., storage ator below 10° C.).

Any of the methods described herein can be performed on patientspresenting to a health care facility (e.g., a hospital, clinic, or anassisted care facility). The subjects may present with one or moresymptoms of a pancreatic β-cell disorder (e.g., any of the symptoms of apancreatic β-cell disorder described herein). The subject may besuspected of having a pancreatic β-cell disorder. The subject can alsopresent with no symptoms (an asymptomatic subject) or just one symptomof a pancreatic β-cell disorder. The subject can have a family historyof a pancreatic β-cell disorder (e.g., type 2 diabetes). The subject canalso have an increased risk of developing a pancreatic β-cell disorder.The subject can be an infant, a child, a teenager, an adult, or anelderly person.

In some embodiments, the methods are performed on a subject that has adetectable or observable pancreatic β-cell mass and/or has detectable orobservable amount pancreatic β-cell function (e.g., a subject that doesnot have a complete loss of pancreatic β-cell mass or pancreatic β-cellfunction). Methods of detecting pancreatic β-cell function are describedherein. Pancreatic β-cell mass can be detected indirectly by observingpancreatic β-cell function in a subject or using methods known in theart (e.g., the methods described in U.S. Patent Application PublicationNo. 20110123443).

The diagnostic methods described herein can be performed by any healthcare professional (e.g., a physician, a laboratory technician, a nurse,a physician's assistant, and a nurse's assistant). The diagnosticmethods described herein can be used in combination with one or moreadditional diagnostic testing methods known in the art or describedherein (e.g., the observation or assessment of one or more symptoms of apancreatic β-cell disorder in a subject, e.g., blood glucose monitoring,glycated hemoglobin analysis, level of insulin, level of IAPP, level ofC-peptide, or ketones in the urine). The diagnostic methods describedherein can be performed on a subject identified as having an increasedrisk of developing a pancreatic β-cell disorder (e.g., a subjectidentified as having an increased risk of developing a pancreatic β-celldisorder using any of the methods described herein). In someembodiments, the diagnostic methods described herein can be performedperiodically (e.g., at least once every month, two months, six months,or year) for a subject that has been identified as having an increasedrisk of developing a pancreatic β-cell disorder. Some embodimentsfurther include collecting the biological sample from the subject.

Some embodiments further include administering to the subject identifiedas having, or at risk of developing, a pancreatic β-cell disorder atreatment for a pancreatic β-cell disorder (e.g., an isolated, purified,or recombinant soluble MANF protein, pioglitazone, GLP-1, or a DPP-4inhibitor (e.g., sitagliptin, vildagliptin, saxagliptin, linagliptin,dutogliptin, gemigliptin, and alogliptin), or any of the compositionsdescribed herein, e.g., an therapeutically effective dose of a solubleMANF protein containing a sequence at least 90% identical to SEQ ID NO:2 and/or apomorphine). Some embodiments further include performingadditional tests to confirm the diagnosis of a pancreatic β-celldisorder in the subject. Some embodiments include selecting the subjectfor periodic glucose monitoring (e.g., periodic self-glucose monitoringusing a glucometer) or any of the monitoring methods described herein.Some embodiments further include selecting the subject for periodicmedical evaluation by a physician or a health care professional (e.g.,periodic visits of at least once every year, at least once every sixmonths, at least once every three months, at least once every twomonths, or at least once a month). Some embodiments further includerecording the results of the diagnostic test in the subject's medicalrecords, or performing a diagnostic test for a pancreatic β-celldisorder on one or more lineal family members of a subject diagnosed ashaving a pancreatic β-cell disorder using the methods described herein.

Methods of Predicting the Risk of Developing a Pancreatic β-CellDisorder

Also provided are methods of predicting a subject's risk of developing apancreatic β-cell disorder. These methods include determining (assaying)a level of soluble MANF in a biological sample from the subject andcomparing the level of the soluble MANF in the biological sample to areference level of soluble MANF. An elevated level of soluble MANF inthe biological sample as compared to the reference level of soluble MANFindicates that the subject has an increased risk of developing apancreatic β-cell disorder, and a decrease or no significant change inthe level of soluble MANF in the biological sample compared to thereference level indicates that the subject has a decreased or nosignificant risk of developing a pancreatic β-cell disorder. Any of thereference levels of soluble MANF described herein can be used in thesemethods. Some embodiments further include obtaining the biologicalsample from the subject.

The levels of soluble MANF can be determined using methods known in theart. For example, the levels of soluble MANF can be detected using anumber of techniques known in the art that utilize antibodies thatspecifically bind to soluble MANF (e.g., enzyme-linked immunosorbentassay). In some embodiments, the methods further include obtaining orcollecting a sample from a subject (e.g., a biological sample containinga biological fluid, e.g., urine, blood, plasma, serum, or cerebrospinalfluid).

Any of the methods described herein can be performed on patientspresenting to a health care facility (e.g., a hospital, clinic, or anassisted care facility). In some embodiments, the methods are performedon a subject as part of a periodic physical examination by a health careprofessional. The subjects may present with one or more symptoms of apancreatic β-cell disorder (e.g., any of the symptoms of a pancreaticβ-cell disorder described herein). The subject may be suspected ofhaving a pancreatic β-cell disorder. The subject can also present withno symptoms (an asymptomatic subject) or just one symptom of apancreatic β-cell disorder. The subject can have a family history of apancreatic β-cell disorder (e.g., type 2 diabetes). The subject can bean infant, a child, a teenager, an adult, or an elderly person.

These methods described herein can be performed by any health careprofessional (e.g., a physician, a laboratory technician, a nurse, aphysician's assistant, and a nurse's assistant). These methods can beused in combination with any additional methods known in the art foridentifying a subject at risk of developing a pancreatic β-cell disorder(e.g., assessment of one of more of the following factors: increasedweight, inactivity, family history of a pancreatic β-cell disorder,race, age, diagnosis with polycystic ovary syndrome, high bloodpressure, decreased high-density lipoprotein levels (e.g., below 35mg/dL), and high levels of triglycerides (e.g., above 250 mg/dL)). Asubject identified as having an increased risk of developing apancreatic β-cell disorder can be monitored using any of the methodsdescribed herein (see, e.g., the next section).

Some embodiments further include administering to a subject identifiedas having an increased risk of developing a pancreatic β-cell disorder atreatment for a pancreatic β-cell disorder (e.g., an isolated, purified,or recombinant soluble MANF protein, pioglitazone, GLP-1, or a DPP-4inhibitor (e.g., sitagliptin, vildagliptin, saxagliptin, linagliptin,dutogliptin, gemigliptin, and alogliptin), or any of the compositionsdescribed herein, e.g., a therapeutically effective dose of a solubleMANF protein containing a sequence at least 90% identical to SEQ ID NO:2 and/or apomorphine). Some embodiments include selecting the subjectidentified as having an increased risk of developing a pancreatic β-celldisorder for periodic glucose monitoring (e.g., periodic self-glucosemonitoring using a glucometer). Some embodiments further includeselecting a subject identified as having an increased risk of developinga pancreatic β-cell disorder for periodic medical evaluation by aphysician or a health care professional (e.g., periodic visits of atleast once every year, at least once every six months, at least onceevery three months, at least once every two months, or at least once amonth). Some embodiments further include recording the results of thetest in the subject's medical records, or performing a similar test orany art-known test to determine the risk of developing a pancreaticβ-cell disorder in one or more lineal family members of a subjectidentified as having an increased risk of developing a pancreatic β-celldisorder using any of the methods described herein.

Methods of Monitoring Pancreatic β-Cell Dysfunction and Pancreaticβ-Cell Mass

Also provided are methods of monitoring pancreatic β-cell dysfunction ina subject (e.g., a subject at risk of developing a pancreatic β-celldisorder, a subject having a pancreatic β-cell disorder, or a subjectthat has received a pancreatic β-cell transplant). These methods includedetermining (assaying) a level of soluble MANF in a biological samplefrom the subject at a first time point, determining (assaying) a levelof soluble MANF in a biological sample from the subject at a second timepoint, and comparing the level of soluble MANF in the biological sampleat the second time point to the level of soluble MANF in the biologicalsample at the first time point. An elevated level of soluble MANF in thebiological sample at the second time point compared to the level ofsoluble MANF at the first time point indicates a decrease (e.g., asignificant, observable, or detectable decrease) in pancreatic β-cellfunction or a decrease in pancreatic β-cell mass in the subject. Adecrease or no significant change in the level of soluble MANF in thebiological sample at the second time point compared to the level ofsoluble MANF in the biological sample at the first time point indicatesno change or an increase in pancreatic β-cell function or pancreaticβ-cell mass in the subject.

In some embodiments, the methods are performed on a subject that has adetectable or observable pancreatic β-cell mass and/or has detectable orobservable amount pancreatic β-cell function at the first and the secondtime point (e.g., a subject that does not have a complete loss ofpancreatic β-cell mass or pancreatic β-cell function at the first andthe second time point).

In some embodiments, the second time point can be at least 6 hours(e.g., at least 12 hours, 18 hours, 24 hours, 1 day, 2 days, 3 days, 4days, 5 days, 6 days, 1 week, 2 weeks, 3 weeks, 1 month, 2 months, 3months, 6 months, 1 year, 2 years, 3 years, 4 years, or 5 years) afterthe first time point. In some embodiments, the first time point can bethe time of admittance into a medical facility or within 1 week of thefirst presentation of at least one symptom of a pancreatic β-celldisorder.

In some embodiments, the methods can further include determining(assaying) a level of soluble MANF in a biological sample from thesubject at one or more additional, later time points. In these methods,an elevated level of soluble MANF in a later sample (collected later inchronological time) compared to the level of soluble MANF in an earlier(e.g., immediately prior) sample (collected earlier in chronologicaltime) indicates a decrease (e.g., a significant, observable, ordetectable decrease) in pancreatic β-cell function or a decrease inpancreatic β-cell mass in the subject. Likewise, a decrease or nosignificant change in the level of soluble MANF in a later sample(collected later in chronological time) compared to the level of solubleMANF in an earlier (e.g., immediately prior) sample (collected earlierin chronological time) indicates no change or an increase in pancreaticβ-cell function or pancreatic β-cell mass in the subject. In someembodiments, these methods are performed on a subject that has adetectable or observable pancreatic β-cell mass and/or has detectable orobservable amount pancreatic β-cell function at the first, the second,and the one or more additional time points (e.g., a subject that doesnot have a complete loss of pancreatic β-cell mass or pancreatic β-cellfunction at the first, the second, and the one or more additional timepoints).

In some embodiments, the subject can have previously received apancreatic β-cell transplant, such that these methods monitor, in part,the pancreatic β-cell function and the pancreatic β-cell mass of thepancreatic β-cell transplanted into the subject. In some embodiments,the transplanted pancreatic β-cells are autografted, homografted, orxenografted pancreatic β-cells. In some embodiments, the transplantedpancreatic β-cells are present within a device, or are surrounded by orplaced within a biocompatible polymer. In some embodiments, thetransplanted pancreatic β-cells are present within a tissue other thanthe pancreas (e.g., liver tissue). In some embodiments, these methodsare performed in a subject within 1 week, 2 weeks, 3 weeks, 1 month, 2months, 3 months, 4 months, 5 months, 6 months, or 1 year of pancreaticβ-cell transplantation. In some embodiments, the first time point isshortly after (e.g., within 1 week or 2 weeks) of the transplantationprocedure.

The levels of soluble MANF can be determined using methods known in theart. For example, the levels of soluble MANF can be detected using anumber of techniques known in the art that utilize antibodies thatspecifically bind to soluble MANF (e.g., enzyme-linked immunosorbentassay). In some embodiments, the methods further include obtaining orcollecting a sample or at least two samples from a subject (e.g., abiological sample containing a biological fluid, e.g., urine, blood,plasma, serum, or cerebrospinal fluid).

Any of the methods described herein can be performed on patientspresenting to a health care facility (e.g., a hospital, clinic, or anassisted care facility). In some embodiments, the methods are performedon a subject as part of a periodic examination by a health careprofessional. The subjects may present with one or more symptoms of apancreatic β-cell disorder (e.g., any of the symptoms of a pancreaticβ-cell disorder described herein). The subject can also present with nosymptoms (an asymptomatic subject) or just one symptom of a pancreaticβ-cell disorder. The subject can have a family history of a pancreaticβ-cell disorder (e.g., type 2 diabetes). The subject can be an infant, achild, a teenager, an adult, or an elderly person.

These methods can be performed by any health care professional (e.g., aphysician, a laboratory technician, a nurse, a physician's assistant,and a nurse's assistant). A subject identified as having a decrease(e.g., a significant, observable, or detectable decrease) in pancreaticβ-cell function or a decrease in pancreatic β-cell mass can beadministered a treatment for a pancreatic β-cell disorder (e.g., anisolated, purified, or recombinant soluble MANF protein, pioglitazone,GLP-1, or a DPP-4 inhibitor (e.g., sitagliptin, vildagliptin,saxagliptin, linagliptin, dutogliptin, gemigliptin, and alogliptin), orany of the compositions described herein, e.g., an therapeuticallyeffective dose of a soluble MANF protein containing a sequence at least90% identical to SEQ ID NO: 2 and/or apomorphine). In some embodiments,e.g., wherein the method includes administering apomorpine, the subjectdoes not have erectile dysfunction or Parkinson's disease.

Some embodiments, further include the additional detection or assessmentof one or more (e.g., two, three, or four) other markers of pancreaticβ-cell dysfunction in the subject (e.g., decreased C-peptide productionand secretion, decreased insulin production and secretion, decreasedIAPP production and secretion, increased blood glucose levels, increasedglycated hemoglobin levels, and the presence of ketones in a biologicalfluid of the subject (e.g., in the urine)). Methods for detecting one ormore additional markers of a pancreatic β-cell dysfunction are known inthe art.

Some embodiments further include administering to a subject identifiedas having an a decrease in pancreatic β-cell function or a decrease inpancreatic β-cell mass a treatment for a pancreatic β-cell disorder(e.g., an isolated, purified, or recombinant soluble MANF protein,pioglitazone, GLP-1, or a DPP-4 inhibitor (e.g., sitagliptin,vildagliptin, saxagliptin, linagliptin, dutogliptin, gemigliptin, andalogliptin), or any of the compositions described herein, e.g., antherapeutically effective dose of a soluble MANF protein containing asequence at least 90% identical to SEQ ID NO: 2 and/or apomorphine).Some embodiments include selecting the subject identified as having adecrease in pancreatic β-cell function or a decrease in pancreaticβ-cell mass for periodic glucose monitoring (e.g., periodic self-glucosemonitoring using a glucometer). Some embodiments further includeselecting a subject identified as having a decrease in pancreatic β-cellfunction or a decrease in pancreatic β-cell mass for periodic medicalevaluation by a physician or a health professional (e.g., periodicvisits of at least once every year, at least once every six months, atleast once every three months, at least once every two months, at leastonce a month, or at least once a week). Some embodiments further includerecording the results of the test in the subject's medical records, orperforming a similar test or any art-known test to monitor pancreaticβ-cell function or pancreatic β-cell mass in one or more lineal familymembers of a subject identified as having a decrease in pancreaticβ-cell function or a decrease in pancreatic β-cell mass. Someembodiments further include selecting a subject having a decrease inpancreatic β-cell function or a decrease in pancreatic β-cell mass forpancreatic β-cell transplantation.

Methods of Monitoring Efficacy of Treatment of a Pancreatic β-cellDisorder

Also provided are methods of monitoring the efficacy of treatment of apancreatic β-cell dysfunction in a subject (e.g., a subject diagnosed ashaving a pancreatic β-cell disorder). These methods include determining(assaying) a level of soluble MANF in a biological sample from thesubject at a first time point, determining (assaying) a level of solubleMANF in a biological sample from the subject at a second time point, andcomparing the level of soluble MANF in the biological sample at thesecond time point to the level of soluble MANF in the biological sampleat the first time point, where (i) the first time point is prior totreatment and the second time point is any time point following theinitiation of treatment, or (ii) the first time point is following theinitiation of treatment and the second time point is at a later timepoint during or after treatment; and a decreased level of soluble MANFin the biological sample at the second time point compared to the levelof soluble MANF in the biological sample at the first time pointindicates that the treatment was effective in the subject. In someembodiments, the treatment of a pancreatic β-cell disorder is theadministration of one or more of an insulin (e.g., any of the forms ofinsulin described herein), pioglitazone, and TUDCA. In some embodiments,the treatment is transplantation of pancreatic β-cells into the subject(e.g., as described herein).

A decreased level of soluble MANF in the biological sample at the secondtime point compared to the level of soluble MANF at the first time pointindicates efficacy of the treatment in the subject. An increased levelor no substantial change in the level of soluble MANF in the biologicalsample at the second time point compared to the level of soluble MANF atthe first time point indicates that the treatment was not effectiveand/or that the present treatment should be terminated and/or analternate therapy should be administered to the subject. In someembodiments, an increased level or no substantial change in the level ofsoluble MANF in the biological sample at the second time point comparedto the level of soluble MANF at the first time point indicates that anincreased dosage of the treatment should be administered to the subjector the treatment should be administered at an increased frequency and/orduration.

In some embodiments, the methods are performed on a subject that has adetectable or observable pancreatic β-cell mass and/or has detectable orobservable amount pancreatic β-cell function at the first and the secondtime point (e.g., a subject that does not have a complete loss ofpancreatic β-cell mass or pancreatic β-cell function at the first andthe second time point). In some embodiments, the methods are performedon a subject that has been previously identified or diagnosed as havinga pancreatic β-cell disorder. Some embodiments further include selectinga subject that has a pancreatic β-cell disorder. Some embodimentsfurther include obtaining a sample from the subject. Some embodimentsfurther include administering one or more doses of a treatment to thesubject.

In some embodiments, the second time point can be at least 6 hours(e.g., at least 12 hours, 18 hours, 24 hours, 1 day, 2 days, 3 days, 4days, 5 days, 6 days, 1 week, 2 weeks, 3 weeks, 1 month, 2 months, 3months, 6 months, 1 year, 2 years, 3 years, 4 years, or 5 years) afterthe first time point. In some embodiments, the first time point can bethe time of admittance into a medical facility or within 1 week of thefirst presentation of at least one symptom of a pancreatic β-celldisorder.

In some embodiments, the methods can further include determining(assaying) a level of soluble MANF in a biological sample from thesubject at one or more additional, later time points. In these methods,a decreased level of soluble MANF in a later sample (collected later inchronological time) compared to the level of soluble MANF in an earlier(e.g., immediately prior) sample (collected earlier in chronologicaltime) indicates efficacy of treatment in the subject. Likewise, anincrease or no significant change in the level of soluble MANF in alater sample (collected later in chronological time) compared to thelevel of soluble MANF in an earlier (e.g., immediately prior) sample(collected earlier in chronological time) indicates that the treatmentwas not effective in the subject. In some embodiments, these methods areperformed on a subject that has a detectable or observable pancreaticβ-cell mass and/or has detectable or observable amount pancreatic β-cellfunction at the first, the second, and the one or more additional timepoints (e.g., a subject that does not have a complete loss of pancreaticβ-cell mass or pancreatic β-cell function at the first, the second, andthe one or more additional time points).

In some embodiments, the subject can have previously received apancreatic β-cell transplant, such that these methods monitor, in part,the efficacy of the pancreatic β-cell transplantation in the subject. Insome embodiments, the transplanted pancreatic β-cells are autografted,homografted, or xenografted pancreatic β-cells. In some embodiments, thetransplanted pancreatic β-cells are present within a device, or aresurrounded by or placed within a biocompatible polymer. In someembodiments, the transplanted pancreatic β-cells are present within atissue other than the pancreas (e.g., liver tissue). In someembodiments, these methods are performed in a subject within 1 week, 2weeks, 3 weeks, 1 month, 2 months, 3 months, 4 months, 5 months, 6months, or 1 year of pancreatic β-cell transplantation. In someembodiments, the first time point is shortly after (e.g., within 1 weekor 2 weeks) of the transplantation procedure.

The levels of soluble MANF can be determined using methods known in theart. For example, the levels of soluble MANF can be detected using anumber of techniques known in the art that utilize antibodies thatspecifically bind to soluble MANF (e.g., enzyme-linked immunosorbentassay). In some embodiments, the methods further include obtaining orcollecting a sample or at least two samples from a subject (e.g., abiological sample containing a biological fluid, e.g., urine, blood,plasma, serum, or cerebrospinal fluid). Any of the methods describedherein can be performed on patients presenting to a health care facility(e.g., a hospital, clinic, or an assisted care facility). In someembodiments, the methods are performed on a subject as part of aperiodic examination by a health care professional. The subjects may bepreviously diagnosed with a pancreatic β-cell disorder and/or maypresent with one or more symptoms of a pancreatic β-cell disorder (e.g.,any of the symptoms of a pancreatic β-cell disorder described herein).The subject can be an infant, a child, a teenager, an adult, or anelderly person.

These methods can be performed by any health care professional (e.g., aphysician, a laboratory technician, a nurse, a physician's assistant,and a nurse's assistant). Some embodiments, further include theadditional detection or assessment of one or more (e.g., two, three, orfour) other markers of a pancreatic β-cell disorder in the subject(e.g., where increased C-peptide production and secretion, increasedinsulin production and secretion, increased IAPP production andsecretion, decreased blood glucose levels, decreased glycated hemoglobinlevels, and the absence or no significant level of ketones in abiological fluid of the subject (e.g., in the urine) at the second timepoint as compared to the corresponding levels at the first time pointfurther indicate that the treatment is effective). Methods for detectingone or more additional markers of a pancreatic β-cell disorder are knownin the art.

Methods of Selecting a Subject for Treatment

Also provided are methods of selecting a subject for treatment of apancreatic β-cell disorder. These methods include determining (assaying)a level of soluble MANF in a biological sample from the subject;comparing the level of soluble MANF in the biological sample to areference level of soluble MANF; and selecting a subject having anelevated level of soluble MANF in the biological sample compared to thereference level for treatment of a pancreatic β-cell disorder. In thesemethods, subjects having a decrease or no significant change in thelevel of soluble MANF in the biological sample compared to the referencelevel are not selected for treatment of a pancreatic β-cell disorder.

Some embodiments can further include assessing or determining the levelof one or more additional markers of a pancreatic β-cell disorder,wherein the detection of one or more additional markers of a pancreaticβ-cell disorder further indicates that the subject should be selectedfor treatment of a pancreatic β-cell disorder. These one or moreadditional markers of a pancreatic β-cell disorder include a decrease inthe level of C-peptide in a biological sample from the subject, adecrease in the level of IAPP in a biological sample from the subject, adecrease in the level of insulin in a biological sample from thesubject, an increase one or more blood glucose level(s) in the subject,an increase in the glycated hemoglobin level in the subject, or thedetection of ketones in a biological sample from the subject (e.g., inthe urine). Methods for detecting the levels of C-peptide, IAPP,insulin, blood glucose, glycated hemoglobin, and ketones in a biologicalsample from the subject are known in the art.

The levels of soluble MANF can be determined using methods known in theart. For example, the levels of soluble MANF can be detected using anumber of techniques known in the art that utilize antibodies thatspecifically bind to soluble MANF (e.g., enzyme-linked immunosorbentassay). In some embodiments, the methods further include obtaining orcollecting a sample from a subject (e.g., a biological sample containinga biological fluid, e.g., urine, blood, plasma, serum, or cerebrospinalfluid). The methods can be performed by any health care professional(e.g., a physician, a nurse, a physician's assistant, a laboratorytechnician, or a nurse's assistant).

The subjects may present with one or more symptoms of a pancreaticβ-cell disorder (e.g., any of the symptoms of a pancreatic β-celldisorder described herein). The subject can also present with nosymptoms or just one symptom of a pancreatic β-cell disorder. Thesubject can be suspected of having a pancreatic β-cell disorder or thesubject can have an increased risk of developing a pancreatic β-celldisorder. The subject can have a family history of a pancreatic β-celldisorder (e.g., type 2 diabetes). The subject can be previouslydiagnosed as having a pancreatic β-cell disorder.

In some embodiments, the methods are performed on a subject that has adetectable or observable pancreatic β-cell mass and/or has detectable orobservable amount pancreatic β-cell function (e.g., a subject that doesnot have a complete loss of pancreatic β-cell mass or pancreatic β-cellfunction).

Treatments of a pancreatic β-cell disorder that can be administered tothe subject include, without limitation: a soluble MANF (e.g., a solubleMANF protein that contains a sequence at least 80% identical to SEQ IDNO: 2, i.e., to the full length of SEQ ID NO:2), apomorphine,rapid-acting insulin (e.g., aspart or lispro insulin), short-acting(e.g., regular insulin), intermediate-acting insulin (e.g., neutralprotamine Hagedorn or NPH insulin), long-acting insulin (e.g.,ultralente insulin), insulin glargine, insulin detemir, pramlintide,incretin mimetics (e.g., exenatide), sulfonylureas (e.g., chorpropamide,glipizide, glyburide, and glimepiride), meglitinides (e.g., repaglinideand nateglinide), biguanides (e.g., metformin), thiazolidinediones(e.g., rosiglitazone and pioglitazone), alpha-glucosidase inhibitors(e.g., acarbose and meglitol), and DPP-4 inhibitors (e.g., sitagliptinand saxagliptin). Treatments of a pancreatic β-cell disorder can includeone or more (e.g., two, three, or four) of the above agents used in anycombination. In some embodiments, e.g., wherein the method includesadministering apomorpine, the subject does not have erectile dysfunctionor Parkinson's disease.

Some embodiments of these methods further include administering to thesubject at least one (e.g., at two, three, or four) treatment for apancreatic β-cell disorder (e.g., one or more of the treatments of apancreatic β-cell disorder described herein or known in the art). Forexample, some embodiments of these methods further include administeringat least one (e.g., at least two, four, six, eight, or ten) dose of anyof the pharmaceutical compositions described herein. The treatment of apancreatic β-cell disorder can continue over a period of time of atleast 1 week, 1 month, 6 months, 1 year, 2 years, 3 years, 4 years, 5years, or 10 years. The treatment can be administered periodically tothe subject (e.g., once a day, twice a day, three times a day, fourtimes a day, once a week, twice a week, three times a week, four times aweek, once a month, twice a month, three times a month, or four times amonth).

In some embodiments, a subject having an elevated level of soluble MANFas compared to the reference level is selected for periodic medicalevaluation by a physician or a health professional (e.g., periodicvisits of at least once every year, at least once every six months, atleast once every three months, at least once every two months, at leastonce a month, or at least once a week). Some embodiments further includerecording in a subject's medical records that the subject should beadministered or prescribed one or more treatment of a pancreatic β-celldisorder (e.g., any of the exemplary treatments described herein). Insome embodiments, a subject having an elevated level of soluble MANF ascompared to the reference level is selected for pancreatic β-celltransplantation.

Methods of Identifying a Subject at Risk of Developing a Pancreaticβ-Cell Disorder

Also provided are methods of identifying a subject at risk of developinga pancreatic β-cell disorder. These methods include determining a levelof soluble MANF in a biological sample from a subject; comparing thelevel of the soluble MANF in the biological sample from the subject to areference level of soluble MANF. A subject is identified as having anincreased risk of developing a pancreatic β-cell disorder if the levelof soluble MANF in the biological sample from the subject is elevatedcompared to the reference level. A subject is identified as having adecreased risk of developing a pancreatic β-cell disorder if the levelof soluble MANF in the biological sample from the subject is decreasedor not significantly changed compared to the reference level.

In any of the methods described herein, the increased risk is relativeto a subject that does not have a significant or observable elevation inthe level of soluble MANF (e.g., a subject that is not diagnosed ashaving a pancreatic β-cell disorder using any of the methods describedherein, a healthy subject is not diagnosed as having a disease, or asubject that does not have a symptom of a pancreatic β-cell disorder ora family history of a pancreatic β-cell disorder).

The levels of soluble MANF may be determined using standard methods(e.g., any of the antibody-based methods known in the art). The methodscan be performed by any health care professional (e.g., a physician, anurse, a physician's assistant, a laboratory technician, or a nurse'sassistant).

The subjects may present with one or more symptoms of a pancreaticβ-cell disorder (e.g., any of the symptoms of a pancreatic β-celldisorder described herein). The subject can also be suspected of havinga pancreatic β-cell disorder. The subject can also present with nosymptoms or just one symptom of a pancreatic β-cell disorder. Thesubject can have a family history of a pancreatic β-cell disorder (e.g.,type 2 diabetes).

In some embodiments, the methods are performed on a subject that has adetectable or observable pancreatic β-cell mass and/or has detectable orobservable amount pancreatic β-cell function (e.g., a subject that doesnot have a complete loss of pancreatic β-cell mass or pancreatic β-cellfunction).

Subjects identified as having an increased risk of developing apancreatic β-cell disorder may be administered a treatment for apancreatic β-cell disorder (e.g., any of the treatments describedherein) or may be administered a new or alternative treatment for apancreatic β-cell disorder. Subjects identified as having an increasedrisk of developing a pancreatic β-cell disorder can also undergo moreaggressive therapeutic treatment (e.g., increased periodicity of clinicor hospital visits).

Some embodiments further include administering to a subject identifiedas having an increased risk of developing a pancreatic β-cell disorder atreatment for a pancreatic β-cell disorder (e.g., an isolated, purified,or recombinant soluble MANF protein, pioglitazone, GLP-1, or a DPP-4inhibitor (e.g., sitagliptin, vildagliptin, saxagliptin, linagliptin,dutogliptin, gemigliptin, and alogliptin), or any of the compositionsdescribed herein, e.g., an therapeutically effective dose of a solubleMANF protein containing a sequence at least 90% identical to SEQ ID NO:2 and/or apomorphine). Some embodiments include selecting the subjecthaving an increased risk of developing a pancreatic β-cell disorder forglucose monitoring (e.g., self-glucose monitoring using a glucometer).Some embodiments further include selecting the subject for periodicmedical evaluation by a physician or a health professional (e.g.,periodic visits of at least once every year, at least once every sixmonths, at least once every three months, at least once every twomonths, or at least once a month). Some embodiments further includerecording the results of the test in the subject's medical records, orperforming a similar test or any art-known test to determine the risk ofdeveloping a pancreatic β-cell disorder in one or more lineal familymembers of a subject identified as having an increased risk ofdeveloping a pancreatic β-cell disorder using the methods describedherein.

Methods of Selecting a Subject for Participation in a Clinical Study

Also provided are methods for selecting a subject for participation in aclinical study. These methods include determining a level of solubleMANF in a biological sample from the subject; comparing the level ofsoluble MANF in the biological sample from the subject to a referencelevel of soluble MANF, and selecting a subject having an elevation, or adecrease or no significant change in the level of soluble MANF in thebiological sample compared to the reference level (e.g., any of thereference levels of soluble MANF described herein) for participation ina clinical study.

The levels of soluble MANF may be determined using standard molecularbiology methods (e.g., any of the antibody-based methods describedherein). The methods can be performed by any health care professional(e.g., a physician, a nurse, a physician's assistant, a laboratorytechnician, or a nurse's assistant).

In some embodiments, the subject may present with one or more symptomsof a pancreatic β-cell disorder (e.g., any of the symptoms of apancreatic β-cell disorder described herein). In some embodiments, thesubject can also present with no symptoms or just one symptom of apancreatic β-cell disorder. In some embodiments, the subject can have afamily history of a pancreatic β-cell disorder (e.g., type 2 diabetes).In some embodiments, the subject can already be diagnosed as having apancreatic β-cell disorder. In some embodiments, the subject is taking atreatment for a pancreatic β-cell disorder. In some embodiments, thesubject is administered a new or alternative treatment for a pancreaticβ-cell disorder during the clinical study.

Methods of Detecting Endoplasmic Reticulum Stress in a Pancreatic β-Cell

Also provided are methods of detecting endoplasmic reticulum stress in apancreatic β-cell that include determining a level of soluble MANFproduced by a pancreatic β-cell, and comparing the level of soluble MANFproduced to a reference level (e.g., any of the reference levels ofsoluble MANF described herein) of soluble MANF. An elevated level ofsoluble MANF produced by the pancreatic β-cell compared to the referencelevel of soluble MANF indicates an increase in endoplasmic reticulumstress in the pancreatic β-cell. A decrease or no significant change inthe level of soluble MANF produced by the pancreatic β-cell compared tothe reference level of soluble MANF indicates that the pancreatic β-cellhas not experienced a detectable level of endoplasmic reticulum stress.

The levels of soluble MANF may be determined using standard molecularbiology methods (e.g., any of the antibody-based methods describedherein). The methods can be performed by any health care professional(e.g., a physician, a nurse, a physician's assistant, a laboratorytechnician, or a nurse's assistant) or a scientist.

In some embodiments, the pancreatic β-cell is in a mammal (e.g., ahuman) and the levels of soluble MANF produced by the pancreatic β-cellcan be determined from a biological sample from the mammal (e.g., asample containing blood, serum, or plasma). In some embodiments, thepancreatic β-cell can be an endogenous pancreatic β-cell or atransplanted pancreatic β-cell (e.g., an autografted, homografted, orxenografted pancreatic β-cell). In some embodiments, the pancreaticβ-cell is an autografted pancreatic β-cell that has been geneticallymodified). In some embodiments, the pancreatic β-cells can be presentwithin a pancreas of the mammal or can be present in a tissue other thanthe pancreas (e.g., the liver). In some embodiments, the pancreaticβ-cells can be present in a device, or a biocompatible material orpolymer.

In some embodiments, the pancreatic β-cell is present in vitro (e.g., ina tissue culture). For example, a primary pancreatic β-cell harvestedfrom a mammal can be cultured ex vivo. In some embodiments, the culturedpancreatic β-cell is a primary mammalian (e.g., human, rat, monkey, cow,or pig) pancreatic β-cell line. In some embodiments, the culturedmammalian pancreatic β-cell can be genetically manipulated (e.g.,genetically modified to express one or more proteins or geneticallymodified to decrease the expression of one or more proteins) orchemically treated (e.g., with one or more growth factors). In someembodiments, the pancreatic β-cell can be cultured in the presence ofone or more biocompatible polymers or biosynthetic materials (e.g.,polymers or materials that aid in the transplantation of the pancreaticβ-cells into a mammal (e.g., a human)). A variety of biocompatiblepolymers and biosynthetic materials are known in the art.

In some embodiments, the detection of endoplasmic reticulum stress inpancreatic β-cells within a subject is followed by one or more of thefollowing: identification of a subject having an increased level ofendoplasmic reticulum stress in his or her pancreatic β-cells,administration of a therapeutic agent (e.g., an agent that will decreaseendoplasmic reticulum stress in pancreatic β-cells, e.g., any of thesoluble MANF proteins described herein and/or apomorphine); monitoringof pancreatic β-cell function (e.g., any of the methods of monitoringpancreatic β-cell function described herein) in the subject; andincreasing the frequency of clinical visits or the level of healthmonitoring (e.g., increased frequency of blood glucose testing) of thesubject. In some embodiments, e.g., wherein the method includesadministering apomorpine, the subject does not have erectile dysfunctionor Parkinson's disease.

In some embodiments, the detection of increased endoplasmic reticulumstress in pancreatic β-cells in vitro is followed by contacting thepancreatic β-cell with a therapeutic agent (e.g., an agent that willdecrease endoplasmic reticulum stress in pancreatic β-cells, e.g., anyof the soluble MANF proteins described herein or apomorphine) and/ormonitoring of pancreatic β-cell function (e.g., any of the methods ofmonitoring pancreatic β-cell function described herein). In any of themethods described herein, the pancreatic β-cell can be cultured in vitrowith at least one other cell type or at least one other cell line (e.g.,co-culture or feeder culture).

Methods of Treatment

Also provided are methods of treating or delaying the onset of apancreatic β-cell disorder in a subject that include administering to asubject an effective amount of a soluble MANF (e.g., a purified,isolated, or recombinant soluble MANF protein (e.g., any of the solubleMANF proteins described herein)) and/or apomorphine. In someembodiments, treating can result in a decrease in the number of symptomsof a pancreatic β-cell disorder (e.g., any of the symptoms describedherein) in a subject or a decrease in the severity, intensity, orfrequency of one or more symptoms of a pancreatic β-cell disorder (e.g.,any of the symptoms described herein). In some embodiments, treating canresult in a delay in the onset or one or more symptoms (an increase inthe time of actual onset of one or more symptoms in a subject notreceiving treatment compared to a subject receiving treatment). Forexample, treating can result in one or more of the following: a decreasein the blood glucose level(s) in a subject, a decrease in the level ofglycated hemoglobin in a subject, a decrease in the rate of loss of theproduction of insulin in a subject, a decrease in the rate of loss ofpancreatic β-cell function in a subject, and a decrease in the rate ofloss of pancreatic β-cell mass in a subject. In some embodiments, e.g.,wherein the method includes administering apomorpine, the subject doesnot have erectile dysfunction or Parkinson's disease.

Soluble MANF

For example, in some embodiments that soluble MANF administered to asubject contains a sequence that is at least 80% identical (e.g., atleast 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%identical) to any one of SEQ ID NOS: 2 and 4-7, i.e., to the full lengthof SEQ ID NOs:2 or 4-7, and optionally, has a biological activity of asoluble MANF protein (described herein). In some embodiments, thesoluble MANF administered to a subject contains a sequence that is atleast 95% identical (e.g., at least 96%, 97%, 98%, 99%, or 100%identical) to SEQ ID NO: 2 (human soluble MANF), i.e., to the fulllength of SEQ ID NO:2, and optionally, has a biological activity ofsoluble MANF (described herein). In some embodiments, the soluble MANFadministered to a subject is SEQ ID NO: 2 or an endogenous (wildtype)form of soluble MANF. In any of these embodiments, the soluble MANF canbe purified or isolated. In any of these embodiments, the soluble MANFcan be a recombinant protein.

The comparison of sequences and determination of percent identitybetween two sequences is accomplished using a mathematical algorithm.The percent identity between two amino acid sequences is determinedusing the Needleman and Wunsch, J. Mol. Biol., 48:444-453, 1970)algorithm, which has been incorporated into the GAP program in the GCGsoftware package (available on the Internet at gcg.com), using either aBlossum 62 matrix or a PAM250 matrix, and a gap weight of 16 and alength weight of 1. The percent identity between two nucleotidesequences is determined using the GAP program in the GCG softwarepackage (also available on the Internet at gcg.com), using aNWSgapdna.CMP matrix, a gap weight of 40, and a length weight of 1.

In general, percent identity between amino acid sequences referred toherein is determined using the BLAST 2.0 program, which is available tothe public at the National Center for Biotechnology Information (NCBI)website. Sequence comparison is performed using an ungapped alignmentand using the default parameters (Blossum 62 matrix, gap existence costof 11, per residue gap cost of 1, and a lambda ratio of 0.85). Themathematical algorithm used in BLAST programs is described in Altschulet al., Nucleic Acids Research 25:3389-3402, 1997.

As noted herein, mammalian forms of soluble MANF have a high degree ofsequence identity. One skilled in the art would recognize that,generally speaking, in order to obtain variants of soluble MANF thathave biological activity (e.g., the ability to treat or delay the onsetof a pancreatic β-cell disorder in a subject, reduce endoplasmicreticulum stress in a pancreatic β-cell, or reduce or delay endoplasmicreticulum stress-induced apoptotic cell death in population of two ormore pancreatic β-cells), residues that are not conserved betweenvarious mammalian species of soluble MANF could be altered or removed,while those residues that are highly conserved should not be altered orremoved. As is known in the art, one skilled in the art can align thevarious sequences for mammalian soluble MANF proteins provided herein toidentify those residues that are highly conserved and those residuesthat are not conserved.

The biological activity of the various forms of soluble MANF can betested by performing various biological activity assays described hereinor those known in the art. For example, the biological activity of asoluble MANF protein can be tested by treating a pancreatic β-cellcultured in the presence or absence of a soluble MANF (e.g., any of thesoluble MANF proteins described herein) and challenging the pancreaticβ-cells with an agent that induces endoplasmic reticulum stress in thepancreatic β-cells. A soluble MANF having biological activity willreduce the amount of endoplasmic reticulum stress or endoplasmicreticulum stress-induced apoptosis observed in the cells contacted withthe soluble MANF and the agent, as compared to the cells not contactedwith the soluble MANF and treated with the agent. For example, a solubleMANF having biological activity can reduce one or more markers ofendoplasmic reticulum stress in a cell treated with an agent thatinduces endoplasmic reticulum stress compared to a cell not treated witha soluble MANF and treated with the agent (e.g., reduce the induction ofglucose-regulated protein-78 (also known as grp78 or BiP) orbcl-2-associated athanogene-1 (bag-1) expression; reduce activation,Golgi translocation, protease cleavage, or nuclear translocation ofactivating transcription factor 6 (ATF6); reduce protein kinase RNA-likeendoplasmic reticulum kinase (PERK) activation, oligomerization, orautohosphorylation; reduce activation of IRE1; decrease phosphorylationof eIF2a; reduce the intron processing of XBP1 mRNA; reduce activationof a JNK signaling pathway; prevent activation and cleavage ofprocaspase 4; and prevent or decrease the shift in the endoplasmicreticulum redox environment (e.g., measured using the redox sensitiveeroGFP protein as described in the Examples)).

A soluble MANF administered to the subject can also contain one or more(e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15) insertions,additions, deletions, or modifications. For example, a soluble MANF canbe covalently attached to a chemical moiety (e.g., a protein (e.g.,albumin), a sugar (e.g., N-linked glycans or O-linked glycans, e.g.,mannose) (see, e.g., Sola et al., J. Pharm. Sci. 98:1123-1245, 2009), ora polymer (e.g., polyethylene glycol)) that significantly increases thehalf-life of the soluble MANF in a subject or increases the thermalstability of the soluble MANF (e.g., during storage). The soluble MANFprotein used in these methods can also include an HIV tat protein or anyother moiety that increases the cellular permeability of the solubleMANF protein.

Several methods are known in the art for the production of a recombinantprotein (e.g., a recombinant soluble MANF) using molecular biology andcell culture techniques. For example, a soluble MANF encoded by a mRNAsequence (e.g., an mRNA containing a sequence at least 80% identical(e.g., at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%,or 100% identical) to SEQ ID NO: 3 can be transfected into a bacterial,yeast, or mammalian cell (using a protein expression plasmid or viralvector) that allows for the expression of the soluble MANF by thetransfected cell. The transfected cells or the culture medium can becollected, and the recombinant soluble MANF protein purified usingmethods known in the art. A number of additional nucleic acids (mRNA)encoding other mammalian soluble MANF proteins are known in the art.

In some embodiments, the subject is first identified or selected fortreatment using any of the diagnostic methods described herein or any ofthe methods of predicting a subject at risk of developing a pancreaticβ-cell disorder described herein or known in the art.

A subject can be administered at least one (e.g., at least 2, 3, 4, or5) dose of a soluble MANF (e.g., any of the soluble MANF proteinsdescribed herein) and/or apomorphine. The soluble MANF and/orapomorphine can be administered to the subject at least once a day(e.g., twice a day, three times a day, and four times a day), at leastonce a week (e.g., twice a week, three times a week, four times a week),and/or at least once a month. A subject can be treated (e.g.,periodically administered a soluble MANF) for a prolonged period of time(e.g., at least one month, two months, six months, one year, two years,three years, four years, or five years). As described in detail herein,the dosage of the soluble MANF and/or apomorphine to be administered tothe subject can be determined by a physician by consideration of anumber of physiological factors including, but not limited to, the sexof the subject, the weight of the subject, the age of the subject, andthe presence of other medical conditions. The soluble MANF and/orapomorphine can be administered to the subject orally, intravenously,intraarterially, subcutaneously, intramuscularly, intracranially, or viainjection into the cerebrospinal fluid. Likewise, the agent may beformulated as a solid (e.g., for oral administration) or aphysiologically acceptable liquid carrier (e.g., saline) (e.g., forintravenous, intraarterial, subcutaneous, intramuscular, orcerebrospinal administration).

In some embodiments, the subject is further administered at least one(e.g., two, three, four, or five) other treatment of a pancreatic β-celldisorder (e.g., any of the treatments for a pancreatic β-cell disorderdescribed herein, e.g., any of the insulins described herein). In someembodiments, the soluble MANF and/or apomorphine is formulated togetherwith at least one (e.g., two, three, or four) other treatment of apancreatic β-cell disorder (e.g., formulated in a physiologicallyacceptable buffer or medium for systemic administration) (e.g., any ofthe pharmaceutical compositions described herein).

Methods of Reducing Endoplasmic Reticulum Stress in a Pancreatic β-Cell

Also provided are methods of reducing endoplasmic reticulum stress in apancreatic β-cell. These methods include contacting the pancreaticβ-cell with an effective amount of one or more (e.g., two or three) ofsoluble MANF (e.g., any of the soluble MANF proteins described herein,e.g., a recombinant, purified, or isolated soluble MANF proteincontaining a sequence at least 80% identical to SEQ ID NO: 2),apomorphine, and pioglitazone. In some embodiments, the pancreaticβ-cell is in vitro (tissue culture). In some embodiments, the pancreaticβ-cell can be in a subject. The pancreatic β-cell used in theseexperiments can be any pancreatic β-cell described herein.

In some embodiments, the pancreatic β-cell can be contacted with one ormore (e.g., two or three) of a soluble MANF, apomorphine, andpioglitazone for an extended period of time (e.g., at least 15 minutes,30 minutes, 1 hour, 2 hours, 6 hours, 8 hours, 10 hours, 12 hours, or 24hours). In some embodiments, the pancreatic β-cell is contacted withseveral doses of one or more (e.g., two or three) of a soluble MANF,apomorphine, and pioglitazone (e.g., at least two doses, three doses,four doses, or five doses), e.g., at regular, timed intervals (e.g.,approximately once a day, once a week, or once a month).

A reduction in endoplasmic reticulum stress can be determined using anymethods known in the art for detecting endoplasmic reticulum stress in acell (e.g., detecting or assessing any of the markers of endoplasmicreticulum stress described herein). For example, a reduction inendoplasmic reticulum stress can be detected by a reduction in one ormore markers of endoplasmic reticulum stress in a cell. In someembodiments, a reduction in endoplasmic reticulum stress can be observedby one or more of the following events: a reduction in the induction ofgrp78 (BiP) or bag-1 expression; a reduction in the activation, Golgitranslocation, protease cleavage, or nuclear translocation of ATF6; areduction in PERK activation, oligomerization, or autohosphorylation; areduction in the activation of IRE1; a reduction in phosphorylation ofeIF2a; a reduction in the intron processing of XBP1 mRNA; a reduction inthe activation of a JNK signaling pathway; a reduction in the activationand cleavage of procaspase 4; and a reduction in the shift in the redoxenvironment of the endoplasmic reticulum induced by exposure to aER-stress inducing agent (e.g., as compared to a control pancreaticβ-cell exposed to a ER-stress inducing agent, but not treated with oneor more (e.g., two or three) of soluble MANF, apomorphine, andpioglitazone). A reduction in the shift in the redox environment of theendoplasmic reticulum can be measured using redox-sensitive dyes orproteins, e.g., the reporter protein described in the Examples. In someembodiments, the reduction in endoplasmic reticulum stress in apancreatic β-cell can be compared to the amount of endoplasmic reticulumstress observed or detected in a pancreatic β-cell not contacted withone or more of soluble MANF, apomorphine, and pioglitazone, respectively(e.g., in vitro or in a subject). In some embodiments, the reduction inendoplasmic reticulum stress in a pancreatic β-cell is relative to acontrol pancreatic β-cell that is not contacted with a soluble MANFprotein, apomorphine, or pioglitazone, but is contacted with an agentthat induces endoplasmic reticulum stress (e.g., thapsigargin).

These methods can be performed by a health care professional (e.g., anyhealth care professional described herein) or a scientist.

Methods of Reducing or Delaying Endoplasmic Reticulum Stress-InducedApoptosis

Pancreatic β-cells having endoplasmic reticulum stress can activateapoptotic pathways within the cell. Also provided herein are methods ofreducing or delaying endoplasmic reticulum stress-induced apoptosis in apopulation of two or more pancreatic β-cells that include contacting thepopulation of pancreatic β-cells with an effective amount of one or more(e.g., two or three) of a soluble MANF (e.g., any of the soluble MANFproteins described herein), apomorphine, and pioglitazone.

In some embodiments, the pancreatic β-cell is in vitro (tissue culture).In some embodiments, the pancreatic β-cell can be in a subject (e.g., inan engrafted biocompatible material or polymer). The pancreatic β-cellsused in these methods can be any pancreatic β-cells described herein. Insome embodiments, the pancreatic β-cell can be contacted with one ormore (e.g., two or three) of a soluble MANF, apomorphine, andpioglitazone for an extended period of time (e.g., at least 15 minutes,30 minutes, 1 hour, 2 hours, 6 hours, 8 hours, 10 hours, 12 hours, or 24hours). In some embodiments, the pancreatic β-cell is contacted withseveral doses of one or more (e.g., two or three) of a soluble MANF,pioglitazone, and apomorphine (e.g., at least two doses, three doses,four doses, or five doses), e.g., at regular timed intervals.

The onset and timing of apoptosis in a pancreatic β-cell population canbe determined using any of the methods described herein or those knownin the art. Contacting a pancreatic β-cell population with one or more(e.g., two or three) of a soluble MANF, apomorphine, and pioglitazonecan mediate a decrease in the percentage of pancreatic β-cells withinthe population that undergo apoptosis (e.g., endoplasmic reticulumstress-induced apoptosis) or delay the onset of apoptosis within thepopulation of pancreatic β-cells. In some embodiments, the decrease ordelay in endoplasmic reticulum stress-induced apoptosis in cells treatedwith one or more (e.g., two or three) of a soluble MANF, apomorphine,and pioglitazone can be compared to a population of pancreatic β-cellsthat are not treated with one or more (e.g., two or three) of a solubleMANF, apomorphine, and pioglitazone. In some embodiments, the decreaseor delay in endoplasmic reticulum stress-induced apoptosis in cellstreated with one or more (e.g., two or three) of a soluble MANF,apomorphine, and pioglitazone can be compared to a control population ofpancreatic β-cells not treated with one or more (e.g., two or three) ofa soluble MANF, apomorphine, and pioglitazone, but contacted with anagent that induces endoplasmic reticulum stress (e.g., thapsigargin).

Methods for detecting apoptotic cell death are well-known in the art andinclude, without limitation, the cleavage of cellular caspases (e.g.,procaspase-3 and procaspase-4), Hoescht and 7-amino-actinomycin uptake,TdT-mediated dUTP nick end labeling assay, and annexin membranestaining. A variety of kits for detecting apoptotic cell death arecommercially available.

Pharmaceutical Compositions

Also provided herein are pharmaceutical compositions that contain atleast one soluble MANF (e.g., any of the soluble MANF proteins describedherein, e.g., a purified, isolated, or recombinant soluble MANF) and/orapomorphine, and at least one other treatment for a pancreatic β-celldisorder (e.g., one or more of any of the treatments of a pancreaticβ-cell disorder described herein, e.g., pioglitazone, TUDCA, and any ofthe insulins described herein).

In some embodiments, the compositions are formulated with apharmaceutically acceptable carrier. The pharmaceutical compositions andformulations can be administered parenterally, orally or by localadministration, such as by aerosol or transdermally. The pharmaceuticalcompositions can be formulated in any way and can be administered in avariety of unit dosage forms depending upon the condition or disease andthe degree of illness, the general medical condition of each patient,the resulting preferred method of administration and the like. Detailson techniques for formulation and administration of pharmaceuticals arewell described in the scientific and patent literature, see, e.g.,Remington: The Science and Practice of Pharmacy, 21st ed., 2005.

The pharmaceutical compositions provided herein may be formulated foradministration, in any convenient way for use in human or veterinarymedicine. Wetting agents, emulsifiers and lubricants, such as sodiumlauryl sulfate and magnesium stearate, as well as coloring agents,release agents, coating agents, sweetening, flavoring, and perfumingagents, preservatives, and antioxidants can also be present in thecompositions.

Formulations of the compositions of the invention include those suitablefor intradermal, inhalation, oral/nasal, topical, and/or parenteraladministration. The formulations may conveniently be presented in unitdosage form and may be prepared by any methods well known in the art ofpharmacy. The amount of active ingredient (e.g., soluble MANF and/orapomorphine, and one or more additional therapeutic agents of apancreatic β-cell disorder) which can be combined with a carriermaterial to produce a single dosage form will vary depending upon thehost being treated, the particular mode of administration, e.g.,intradermal or inhalation. The amount of active ingredient which can becombined with a carrier material to produce a single dosage form willgenerally be that amount of the compound which produces a therapeuticeffect (e.g., one or more of any of the therapeutic effects describedherein).

Pharmaceutical formulations of this invention can be prepared accordingto any method known to the art for the manufacture of pharmaceuticals.Such drugs can contain sweetening agents, flavoring agents, coloringagents, and preserving agents. A formulation can be admixed withnontoxic pharmaceutically acceptable excipients which are suitable formanufacture. Formulations may comprise one or more diluents,emulsifiers, preservatives, buffers, excipients, etc., and may beprovided in such forms as liquids, powders, emulsions, lyophilizedpowders, sprays, creams, lotions, controlled release formulations,tablets, pills, gels, on patches, in implants, etc.

Pharmaceutical formulations for oral administration can be formulatedusing pharmaceutically acceptable carriers well known in the art inappropriate and suitable dosages. Such carriers enable thepharmaceuticals to be formulated in unit dosage forms as tablets, pills,powder, dragees, capsules, liquids, lozenges, gels, syrups, slurries,suspensions, etc., suitable for ingestion by the patient. Pharmaceuticalpreparations for oral use can be formulated as a solid excipient,optionally grinding a resulting mixture, and processing the mixture ofgranules, after adding suitable additional compounds, if desired, toobtain tablets or dragee cores. Suitable solid excipients arecarbohydrate or protein fillers include, e.g., sugars, includinglactose, sucrose, mannitol, or sorbitol; starch from corn, wheat, rice,potato, or other plants; cellulose such as methyl cellulose,hydroxypropylmethyl-cellulose, or sodium carboxy-methylcellulose; andgums including arabic and tragacanth; and proteins, e.g., gelatin andcollagen. Disintegrating or solubilizing agents may be added, such asthe cross-linked polyvinyl pyrrolidone, agar, alginic acid, or a saltthereof, such as sodium alginate. Push-fit capsules can contain activeagents mixed with a filler or binders, such as lactose or starches,lubricants, such as talc or magnesium stearate, and, optionally,stabilizers. In soft capsules, the active agents can be dissolved orsuspended in suitable liquids, such as fatty oils, liquid paraffin, orliquid polyethylene glycol with or without stabilizers.

Aqueous suspensions can contain an active agent (e.g., a soluble MANFand/or apomorphine, and one or more additional treatments of apancreatic β-disorder) in admixture with excipients suitable for themanufacture of aqueous suspensions, e.g., for aqueous intradermalinjections. Such excipients include a suspending agent, such as sodiumcarboxymethylcellulose, methylcellulose, hydroxypropylmethylcellulose,sodium alginate, polyvinylpyrrolidone, gum tragacanth, and gum acacia,and dispersing or wetting agents such as a naturally-occurringphosphatide (e.g., lecithin), a condensation product of an alkyleneoxide with a fatty acid (e.g., polyoxyethylene stearate), a condensationproduct of ethylene oxide with a long-chain aliphatic alcohol (e.g.,heptadecaethylene oxycetanol), a condensation product of ethylene oxidewith a partial ester derived from a fatty acid and a hexitol (e.g.,polyoxyethylene sorbitol mono-oleate), or a condensation product ofethylene oxide with a partial ester derived from fatty acid and ahexitol anhydride (e.g., polyoxyethylene sorbitan mono-oleate). Theaqueous suspension can also contain one or more preservatives such asethyl or n-propyl p-hydroxybenzoate, one or more coloring agents, one ormore flavoring agents, and one or more sweetening agents, such assucrose, aspartame, or saccharin. Formulations can be adjusted forosmolarity.

In some embodiments, oil-based pharmaceuticals are used foradministration. Oil-based suspensions can be formulated by suspendingactive agents in a vegetable oil, such as arachis oil, olive oil, sesameoil, or coconut oil, or in a mineral oil, such as liquid paraffin; or amixture of these. See, e.g., U.S. Pat. No. 5,716,928, describing usingessential oils or essential oil components for increasingbioavailability and reducing inter- and intra-individual variability oforally administered hydrophobic pharmaceutical compounds (see also, U.S.Pat. No. 5,858,401). The oil suspensions can contain a thickening agent,such as beeswax, hard paraffin, or cetyl alcohol. Sweetening agents canbe added to provide a palatable oral preparation, such as glycerol,sorbitol, or sucrose. These formulations can be preserved by theaddition of an antioxidant such as ascorbic acid. As an example of aninjectable oil vehicle, see Minto, J. Pharmacol. Exp. Ther. 281:93-102,1997.

Pharmaceutical formulations can also be in the form of oil-in-wateremulsions. The oily phase can be a vegetable oil or a mineral oil,described above, or a mixture of these. Suitable emulsifying agentsinclude naturally-occurring gums, such as gum acacia and gum tragacanth,naturally-occurring phosphatides, such as soybean lecithin, esters, orpartial esters derived from fatty acids and hexitol anhydrides, such assorbitan mono-oleate, and condensation products of these partial esterswith ethylene oxide, such as polyoxyethylene sorbitan mono-oleate. Theemulsion can also contain sweetening agents and flavoring agents, as inthe formulation of syrups and elixirs. Such formulations can alsocontain a demulcent, a preservative, or a coloring agent. In alternativeembodiments, these injectable oil-in-water emulsions of the inventioncomprise a paraffin oil, a sorbitan monooleate, an ethoxylated sorbitanmonooleate, and/or an ethoxylated sorbitan trioleate.

The pharmaceutical compounds can also be administered by in intranasalor intraocular routes including insufflation, powders, and aerosolformulations (for examples of steroid inhalants, see e.g., Rohatagi, J.Clin. Pharmacol. 35:1187-1193, 1995; Tjwa, Ann. Allergy Asthma Immunol.75:107-111, 1995).

In some embodiments, the pharmaceutical compounds can be deliveredtransdermally, by a topical route, formulated as applicator sticks,solutions, suspensions, emulsions, gels, creams, ointments, pastes,jellies, paints, powders, and aerosols.

In some embodiments, the pharmaceutical compounds can also be deliveredas microspheres for slow release in the body. For example, microspherescan be administered via intradermal injection of drug which slowlyrelease subcutaneously; see Rao, J. Biomater Sci. Polym. Ed. 7:623-645,1995; as biodegradable and injectable gel formulations, see, e.g., Gao,Pharm. Res. 12:857-863, 1995; or, as microspheres for oraladministration, see, e.g., Eyles, J. Pharm. Pharmacol. 49:669-674, 1997.

In some embodiments, the pharmaceutical compounds can be parenterallyadministered, such as by intravenous (IV), intramuscular,intraperitoneal, or subcutaneous administration, or administration intoa body cavity, a lumen of an organ, or into the cerebrospinal fluid of asubject. These formulations can comprise a solution of active agentdissolved in a pharmaceutically acceptable carrier. Acceptable vehiclesand solvents that can be employed are water and Ringer's solution, or anisotonic sodium chloride. In addition, sterile fixed oils can beemployed as a solvent or suspending medium. For this purpose any blandfixed oil can be employed including synthetic mono- or diglycerides. Inaddition, fatty acids, such as oleic acid can likewise be used in thepreparation of injectables. These solutions are sterile and generallyfree of undesirable matter. These formulations may be sterilized byconventional, well known sterilization techniques. The formulations maycontain pharmaceutically acceptable auxiliary substances as required toapproximate physiological conditions such as pH adjusting and bufferingagents, toxicity adjusting agents, e.g., sodium acetate, sodiumchloride, potassium chloride, calcium chloride, sodium lactate, and thelike. The concentration of active agent in these formulations can varywidely, and will be selected primarily based on fluid volumes,viscosities, body weight, and the like, in accordance with theparticular mode of administration selected and the patient's needs. ForIV administration, the formulation can be a sterile injectablepreparation, such as a sterile injectable aqueous or oleaginoussuspension. This suspension can be formulated using those suitabledispersing or wetting agents and suspending agents. The sterileinjectable preparation can also be a suspension in a nontoxicparenterally-acceptable diluent or solvent, such as a solution of1,3-butanediol. The administration can be by bolus or continuous (e.g.,substantially uninterrupted introduction into a blood vessel for aspecified period of time).

In some embodiments, the pharmaceutical compounds and formulations canbe lyophilized. Stable lyophilized formulations comprising a solubleMANF and/or apomorphine, and one or more additional treatments of apancreatic β-cell disorder can be made by lyophilizing a solutioncomprising a soluble MANF and/or apomorphine, and the one or moreadditional treatments and a bulking agent, e.g., mannitol, trehalose,raffinose, and sucrose, or mixtures thereof. A process for preparing astable lyophilized formulation can include lyophilizing a solution about2.5 mg/mL protein, about 15 mg/mL sucrose, about 19 mg/mL NaCl, and asodium citrate buffer having a pH greater than 5.5, but less than 6.5.See, e.g., US2004/0028670.

The compositions and formulations can be delivered by the use ofliposomes. By using liposomes, particularly where the liposome surfacecarries ligands specific for target cells, or are otherwisepreferentially directed to a specific organ, one can focus the deliveryof the active agent into target cells in vivo. See, e.g., U.S. Pat. Nos.6,063,400 and 6,007,839; Al-Muhammed, J. Microencapsul. 13:293-306,1996; Chonn, Curr. Opin. Biotechnol. 6:698-708, 1995; and Ostro, Am. J.Hosp. Pharm. 46:1576-1587, 1989.

The formulations of the invention can be administered for prophylacticand/or therapeutic treatments. In some embodiments, for therapeuticapplications, compositions are administered to a subject who is at riskof or has a disorder described herein, in an amount sufficient to cure,alleviate or partially arrest the clinical manifestations of thedisorder or its complications; this can be called a therapeuticallyeffective amount. For example, in some embodiments, pharmaceuticalcompositions of the invention are administered in an amount sufficientto reduce the number of symptoms or reduce the severity, duration, orfrequency of one or more symptoms of a pancreatic β-cell disorder in asubject.

The amount of pharmaceutical composition adequate to accomplish this isa therapeutically effective dose. The dosage schedule and amountseffective for this use, i.e., the dosing regimen, will depend upon avariety of factors, including the stage of the disease or condition, theseverity of the disease or condition, the general state of the patient'shealth, the patient's physical status, age, and the like. In calculatingthe dosage regimen for a patient, the mode of administration also istaken into consideration.

The dosage regimen also takes into consideration pharmacokineticsparameters well known in the art, i.e., the active agents' rate ofabsorption, bioavailability, metabolism, clearance, and the like (see,e.g., Hidalgo-Aragones, J. Steroid Biochem. Mol. Biol. 58:611-617, 1996;Groning, Pharmazie 51:337-341, 1996; Fotherby, Contraception 54:59-69,1996; Johnson, J. Pharm. Sci. 84:1144-1146, 1995; Rohatagi, Pharmazie50:610-613, 1995; Brophy, Eur. J. Clin. Pharmacol. 24:103-108, 1983;Remington: The Science and Practice of Pharmacy, 21st ed., 2005). Thestate of the art allows the clinician to determine the dosage regimenfor each individual patient, the active agents, and disease or conditiontreated. Guidelines provided for similar compositions used aspharmaceuticals can be used as guidance to determine the dosageregiment, i.e., dose schedule and dosage levels, administered practicingthe methods of the invention are correct and appropriate.

Single or multiple administrations of formulations can be givendepending on for example: the dosage and frequency as required andtolerated by the patient, and the like. The formulations should providea sufficient quantity of the active agents to effectively treat, preventor ameliorate conditions, diseases, or symptoms.

In alternative embodiments, pharmaceutical formulations for oraladministration are in a daily amount of between about 1 to 100 or moremg per kilogram of body weight per day. Lower dosages can be used, incontrast to administration orally, into the blood stream, into a bodycavity or into a lumen of an organ. Substantially higher dosages can beused in topical or oral administration or administering by powders,spray, or inhalation. Actual methods for preparing parenterally ornon-parenterally administrable formulations will be known or apparent tothose skilled in the art and are described in more detail in suchpublications as Remington: The Science and Practice of Pharmacy, 21sted., 2005.

Kits

Also provided are kits that contain at least one antibody orantigen-binding antibody fragment (e.g., Fab, F(ab′)₂, Fab′, scFv,di-scFv, or sdAb) that specifically binds to a soluble MANF protein(e.g., any of the soluble MANF proteins described herein) and at leastone (e.g., two, three, or four) antibody or antigen-binding antibodyfragment that specifically binds to one other marker of a pancreaticβ-cell disorder (e.g., insulin, C-protein, and IAPP). In someembodiments, the antibodies or antigen-binding antibody fragmentsincluded in the kits are localized on a substrate (e.g., anenzyme-linked immunosorbent assay). In some embodiments, the kits canfurther include an isolated, purified, or recombinant soluble MANFprotein (e.g., any of the soluble MANF proteins described herein). Insome embodiments, one or more of the antibodies or antigen-bindingantibody fragments is/are labeled (e.g., a radioisotope, a fluorophore,or a binding protein (e.g., avidin)). These kits can be useful for,e.g., for diagnosing a pancreatic β-cell disorder, identifying a subjectat risk of developing a pancreatic β-cell in a subject, or monitoringpancreatic β-cell function or pancreatic β-cell mass in a subject. Insome embodiments, the kits can further contain instructions forperforming any of the methods described herein.

Reporter Proteins

The methods provided herein use reporter proteins that contain a bindingprotein (BiP) signal sequence (e.g., a mouse or a human BiP signalsequence), a redox-sensitive fluorescent protein (e.g., aredox-sensitive green fluorescent protein and a redox-sensitive yellowfluorescent protein), and the amino acid sequence KDEL (Lys-Asp-Glu-Leu,SEQ ID NO:16). In some embodiments, the BiP signal sequence is at theN-terminus, the redox-sensitive fluorescent protein is C-terminal to theBiP signal sequence, and the amino acid sequence KDEL (SEQ ID NO:16) isC-terminal to the redox-sensitive fluorescent protein. In someembodiments, there are 1 to 100 amino acids (e.g., 1 to 50, 1 to 40, 1to 30, 1 to 25, 1 to 20, 1 to 15, and 1 to 10 amino acids) between twoor more of the individual protein elements present in the reporterprotein (e.g., BiP signal sequence, the redox-sensitive fluorescentprotein, and the KDEL (SEQ ID NO:16) sequence). The amino acid sequenceof a redox-sensitive green fluorescent protein is listed below.

Redox Sensitive Green Fluorescent Protein (SEQ ID NO: 10)MSKGEELFTG VVPILVELDG DVNGHKFSVS GEGEGDATYGKLTLKFIVTT GKLPVPWPTL VTTFXLQCFA RYPDHMKRHDFFKSAMPEGY VQERTIFFKD DGNYKTRAEV KFEGDTLVNRIELKGIDFKE DGNILGHKLE YNYNSHCVYI VADKQKNGIKVNFKIRHNIE DGSVQLADHY QQNTPIGDGP VLLPDNHYLCYQSALSKDPN EKRDHMVLLE FVTAAGITHG MDELYK

The reporter proteins described herein can contain a sequence at least80% identical (e.g., at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%,97%, 98%, or 99%) to SEQ ID NO: 10 (as long as the resulting proteinmaintains its redox-sensitive fluorescence properties). For example,mutations introduced into a redox-sensitive green fluorescent protein ora redox-sensitive yellow fluorescent protein should not includemutations in the cysteines. In some embodiments, the redox-sensitivefluorescent protein is a redox-sensitive yellow fluorescent protein(e.g., rxYFP; described in Ostergaard et al., EMBO J. 20:5853-5862,2001). Additional examples of redox-sensitive fluorescent proteins aredescribed in Merksamer et al. (Cell 135:933-947, 2008) and Dooley et al.(J. Biol. Chem. 279:22284-22293, 2004).

Exemplary human and mouse BiP signal sequences that can be present inthe reporter protein are shown below. The reporter proteins used in themethods described herein can contain any mammalian BiP signal sequence(e.g., a human or mouse BiP signal sequence).

In some embodiments, the reporter protein and nucleic acids encodingthese reporter proteins provides a means for sensitive (e.g.,significantly improved) detection of subtle fluctuations in the redoxenvironment within an intact pancreatic β-cell.

Human BiP Signal Sequence (SEQ ID NO: 12) MKLSLVAAMLLLLSAARAMouse BiP Signal Sequence (SEQ ID NO: 13) MMKFTVAAALLLLGAVRA

In some embodiments, the reporter protein contains a sequence that is atleast 80% identical (e.g., at least 85%, 90%, 91%, 92% 93%, 94%, 95%,96%, 97%, 98%, 99%, or 100% identical) to a reporter protein containingthe sequence of SEQ ID NO: 14 (shown below). In some embodiments, thereporter protein is encoded by a nucleic acid containing a sequence thatis at least 80% identical (e.g., at least 85%, 90%, 91%, 92%, 93%, 94%,95%, 96%, 97%, 98%, 99%, or 100% identical) to SEQ ID NO: 15. Forexample, mutations in the reporter protein of SEQ ID NO: 14 should notinclude mutations in the cysteines. Different mutants of SEQ ID NO: 14can be tested using any of the methods described herein to determinewhether the mutants maintain their redox-dependent fluorescenceproperties. The specific redox-dependent fluorescence properties of aprotein containing a sequence at least 80% identical to SEQ ID NO: 14(MEROS-GFP) are described in detail in the Examples.

MEROS-GFP protein (SEQ ID NO: 14)MMKFTVVAAALLLLGAVRAEEEDPPVATMSKGEELFTGVVPILVELDGDVNGHKFSVSGEGEGDATYGKLTLKFISTTGKLPVPWPTLVTTFSYGVQCFSRYPDHMKRHDFFKSAMPEGYVQERTIFFKDDGNYKTRAEVKFEGDTLVNRIELKGIDFKEDGNILGHKLEYNYNCHKVYIMADKQKNGIKVNFKIRHNIEDGSVQLADHYQQNTPIGDGPVLLPDNHYLKTCSALSKDPNEKRDHMVLLERVTAAGITHGMDELYKTSGGPPPTGEEDTSEKDEL MEROS-GFP mRNA (SEQ ID NO: 15)atgatgaagttcactgtggtggcggcggcgttgctgctgctgggcgcggtgcgggccgaggaggaggatccaccggtcgccaccatgagtaaaggagaagaacttttcactggagttgtcccaattcttgttgaattagatggtgatgttaatgggcacaaattttctgtcagtggagagggtgaaggtgatgcaacatacggaaaacttacccttaaatttataccactactggaaaactacctgttccatggccaacacttgtcactactttcagttatggtgttcaatgctatcaagatacccagatcatatgaaacggcatgactattcaagagtgccatgcccgaaggttatgtacaggaaagaactatatttttcaaagatgacgggaactacaagacacgtgctgaagtcaagtttgaaggtgatacccttgttaatagaatcgagttaaaaggtattgattttaaagaagatggaaacattcttggacacaaattggaatacaactataactgccacaaggtatacatcatggcagacaaacaaaagaatggaatcaaagttaacttcaaaattagacacaacattgaagatggaagcgttcaactagcagaccattatcaacaaaatactccaattggcgatggccctgtcdtttaccagacaaccattacctgaagacatgctctgccctttcgaaagatcccaacgaaaagagagaccacatggtccttcttgagcgcgtaacagctgctgggattacacatggcatggatgaactatacaaaactagtggaggccctcccccaactggtgaagaggataca tcagaaaaagatgagttgtagMethods of Screening for Candidate Agents

Also provided are methods of screening for a candidate compound usefulfor one of more of the following: treating or delaying the onset of apancreatic β-cell disorder in a subject, decreasing endoplasmicreticulum stress in a pancreatic β-cell, and reducing or delayingendoplasmic reticulum stress-induced apoptotic cell death in pancreaticβ-cells. These methods include providing a pancreatic β-cell, contactingthe pancreatic β-cell with a candidate compound, and determining thelevel of soluble MANF produced by the pancreatic β-cell in the presenceof the candidate compound, and comparing the level of soluble MANFproduced by the pancreatic β-cell to a reference level of soluble MANF.In these methods, an elevated level of soluble MANF produced by thepancreatic β-cell compared to the reference level indicates that thetest compound may be useful for one or more of the following: treatingor delaying the onset of a pancreatic β-cell disorder in a subject,decreasing endoplasmic reticulum stress in a pancreatic β-cell, andreducing or delaying endoplasmic reticulum stress-induced apoptotic celldeath in pancreatic β-cells.

The pancreatic β-cell(s) used in these methods can be any of thepancreatic β-cells described herein (e.g., a pancreatic β-cell line(e.g., any of the pancreatic β-cell lines described herein) or primarypancreatic β-cells).

The levels of soluble MANF may be determined using standard molecularbiology methods (e.g., any of the antibody-based methods describedherein). The methods can be performed by any health care professional(e.g., a physician, a nurse, a physician's assistant, a laboratorytechnician, or a nurse's assistant) or a scientist.

In some embodiments, the reference level is a level of soluble MANFproduced by a pancreatic β-cell in the absence of the candidatecompound. In some embodiments, the reference level is a level of solubleMANF present in a subject that does not have a pancreatic β-celldisorder, does not have a symptom of a pancreatic β-cell disorder, or afamily history of a pancreatic β-cell disorder. In some embodiments, thereference level is a level of soluble MANF produced in a primarypancreatic β-cell from a mammal or a mammalian pancreatic β-cell line.In some embodiments, the reference level is a threshold level of solubleMANF.

Also provided are methods of screening for a candidate compound usefulfor treating or delaying the onset of a pancreatic β-cell disorder in asubject, decreasing endoplasmic reticulum stress in a pancreatic β-cell,and/or reducing or delaying endoplasmic reticulum stress-inducedapoptotic cell death in pancreatic β-cells. These methods includeproviding a mammalian cell (e.g., a mammalian pancreatic β-cell orpancreatic β-cell line) expressing a reporter protein containing from aBiP signal sequence, a redox-sensitive fluorescent protein, and theamino acid sequence KDEL; contacting the cell with a test compound;determining the amount of oxidized reporter protein present in the cell;and comparing the amount of oxidized reporter protein present in thecell compared to a reference level; where an elevated level of oxidizedreporter protein in the cell compared to the reference level indicatesthat the candidate compound may be useful for treating or delaying theonset of a pancreatic β-cell disorder in a subject, decreasingendoplasmic reticulum stress in a pancreatic β-cell, and/or reducing ordelaying endoplasmic reticulum stress-induced apoptotic cell death inpancreatic β-cells. In some embodiments, the reference level is theamount of the oxidized reporter protein present in a mammalian cell inthe absence of the candidate agent. In some embodiments, the cell iscontacted with both the candidate agent and an agent that induces ERstress and the reference level is a level of oxidized reporter proteinpresent in a cell treated with the agent that induces ER stress alone.Non-limiting examples of agents that induce ER stress are describedherein. Additional examples of agents that induce ER stress are known inthe art. In some embodiments, the reference level is a threshold levelof oxidized reporter protein. The cells used can be human, mouse, rat,pig, monkey, or bovine cells. The cells can be any pancreatic β-cellline described herein or known in the art. In some embodiments, thereporter protein is SEQ ID NO: 14, or a protein containing a sequencethat is at least 80% (e.g., at least 85%, 90%, 95%, 96%, 97%, 98%, or99% identical) to SEQ ID NO: 14.

Also provided are methods of screening for a candidate compound usefulfor treating or delaying the onset of a pancreatic β-cell disorder in asubject, decreasing endoplasmic reticulum stress in a pancreatic β-cell,and/or reducing or delaying endoplasmic reticulum stress-inducedapoptotic cell death in pancreatic β-cells. The methods includeproviding a mammalian cell (e.g., a mammalian pancreatic β-cell)expressing a reporter protein containing from a BiP signal sequence, aredox-sensitive fluorescent protein, and the amino acid sequence KDEL;contacting the cell with a test compound; determining the amount ofreduced reporter protein present in the cell; and comparing the amountof reduced reporter protein present in the cell compared to a referencelevel; where an increased level of reduced reporter protein in the cellcompared to the reference level indicates that the candidate compoundmay be useful for treating or delaying the onset of a pancreatic β-celldisorder in a subject, decreasing endoplasmic reticulum stress in apancreatic β-cell, and/or reducing or delaying endoplasmic reticulumstress-induced apoptotic cell death in pancreatic β-cells. In someembodiments, the reference level is the amount of the reduced reporterprotein present in a mammalian cell in the absence of the candidateagent. In some embodiments, the cell is contacted with both thecandidate agent and an agent that induces ER stress and the referencelevel is a level of reduced reporter protein present in a cell treatedwith the agent that induces ER stress alone. Non-limiting examples ofagents that induce ER stress are described herein. Additional examplesof agents that induce ER stress are known in the art. In someembodiments, the reference level is a threshold level of reducedreporter protein. The cells used can be human, mouse, rat, pig, monkey,or bovine cells. The cells can be any pancreatic β-cell line describedherein or known in the art. In some embodiments, the reporter protein isSEQ ID NO: 14, or a protein containing a sequence that is at least 80%(e.g., at least 85%, 90%, 95%, 96%, 97%, 98%, or 99% identical) to SEQID NO: 14.

In some embodiments, the determining is performed by detecting one ormore fluorescence properties of the reporter protein in the cell (e.g.,detecting spectral features that are unique for the reduced or oxidizedform of the reporter protein). In some embodiments, the level of thereduced or oxidized form of the reporter protein is determined using afluorescent plate reader or using fluorescence-assisted cell sorting(FACS).

For example, pancreatic β-cells (e.g., INS-1 832/13) expressing thereporter protein can be plated into 6-well plates, contacted with acandidate compound, and then harvested by trypsinization. After washingwith phosphate buffered saline, the cells can be suspended in a suitablemedium (e.g., 11 mM glucose-Hanks buffered salt solution), and FACSperformed with LSRII (BD) to determine the levels of the reduced oroxidized form of the reporter protein present in the cell.

In some embodiments, a fluorescent plate reader can be used to determinethe level of the reduced or oxidized form of the reporter proteinpresent in the cell. For example, a pancreatic β-cell line (e.g., INS-1832/13 cells) can be plated into 96-well plates and treated with acandidate agent. The levels of the reduced or oxidized form of thereporter protein can be detected using the fluorescent plate reader. Insuch embodiments, the substraction of background signal should beperformed prior to determining the level of the reduced or oxidized formof the reporter protein.

In some embodiments, the reporter protein contains SEQ ID NO: 14 or aprotein containing a sequence that is at least 80% identical to SEQ IDNO: 14. In these embodiments, the reduced form of the reporter proteinhas an excitation wavelength of 473 nm and an emission wavelength of 510nm, and the oxidized form of the reporter protein has an excitationwavelength of 394 nm and an emission wavelength of 510 nm.

In some embodiments of these methods, a ratio of the level of thereduced form of the reporter protein to the level of the oxidized formof the reporter protein in the cell can be determined. In these methods,the calculated ratio can be compared to a reference ratio. The referenceratio can be the ratio from a cell that is not treated with a candidateagent. The reference ratio can also be a threshold ratio. In someembodiments, the cell is contacted with a candidate agent and an agentthat induces ER stress, the ratio of the level of the reduced form ofthe reporter protein to the level of the oxidized form of the reporterprotein in the cell is determined, and the ratio in the cell is comparedto a reference ratio from a cell treated with the agent that induces ERstress alone. In these methods, a candidate agent that decreases theratio in the cell as compared to the reference ratio is identified as acandidate agent for treating a pancreatic β-cell disorder in a subject.

Some embodiments of the above methods further include testing thecandidate compound in an animal model of a pancreatic β-cell disorder(e.g., determining whether administration of the candidate compound willtreat (e.g., reduce the severity, frequency, or duration) one or moresymptoms of a pancreatic β-cell disorder in an animal model or delay theonset of one or more symptoms of a pancreatic β-cell disorder in ananimal model). Non-limiting animal models of type 2 diabetes includeZucker fatty rats (ZFR), ob/ob (obese) mice, cp (corpulent) rats, Zuckerdiabetic fatty (ZDF) rats, sand rats (Psammomys obesus), obsess rhesusmonkeys, KK mice, and KK-AY mice (described in Srinivasan et al., IndianJ. Med. Res. 125:451-472, 2007). Non-limiting animal models of type 1diabetes include non-obese diabetic (NOD) mice and bio breeding (BB)rats (described in Rees et al., Diabetic Med. 22:359-370, 2005). Theseverity or onset of one or more symptoms of a pancreatic β-celldisorder can be determined or observed in these animals using themethods described herein or methods known in the art.

Some embodiments of the above methods further include testing whetherthe candidate compound will decrease or delay endoplasmic reticulumstress-induced apoptotic cell death in a population of pancreaticβ-cells (e.g., a reduction or delay in endoplasmic reticulumstress-induced apoptotic cell death in a population of pancreaticβ-cells treated with the candidate agent and an agent that inducesendoplasmic reticulum stress compared to a population of pancreaticβ-cells treated with the agent that induces endoplasmic reticulum stressin the absence of the candidate agent). Methods for detecting apoptoticcell death are well-known in the art and include, without limitation,the cleavage of cellular caspases (e.g., procaspase-3 and procaspase-4),Hoescht and 7-amino-actinomycin uptake, TdT-mediated dUTP nick endlabeling assay, and annexin membrane staining. A variety of kits fordetecting apoptotic cell death are commercially available.

Some embodiments of the above methods further include testing whetherthe candidate compound prevents or delays the induction of other markersof endoplasmic reticulum stress in a pancreatic β-cell (e.g., whetherthe candidate compound reduces the induction of grp78 (BiP) or bag-1expression; reduces activation, Golgi translocation, protease cleavage,or nuclear translocation of ATF6; reduces PERK activation,oligomerization, or autohosphorylation; reduce activation of IRE1;decreases phosphorylation of eIF2α; reduces the intron processing ofXBP1 mRNA; reduces activation of a JNK signaling pathway; preventsactivation and cleavage of procaspase 4; and/or prevents or decrease theshift in the endoplasmic reticulum redox environment (e.g., measuredusing any of the reporter proteins described herein)). Expression levelsof BiP and Bag-1 can be determined using quantitative real-time PCR withsets of primers that are designed to hybridize to portions of BiP orBag-1. Expression levels or the processing, activation, phosphorylation,or cellular localization of BiP, Bag-1, PERK, IRE1, eIF2α, XBP1, andATF6 can also be determined using antibodies that specifically bind toone BiP, Bag-1, PERK, IRE1, eIF2α, XBP1, or ATF6 using methods known inthe art. In some embodiments, the prevention or delay in one or moremarkers of endoplasmic reticulum stress is cells treated with thecandidate agent and an agent that induces endoplasmic reticulum stressis compared to pancreatic β-cell(s) treated with the agent that inducesendoplasmic reticulum stress in the absence of the candidate agent.

Any type of candidate compound can used in the above methods. Acandidate compound, e.g., can be a protein, a peptide, a nucleic acid(e.g., RNA or DNA), an inorganic compound, a lipid, an oligosaccharide,or any combination thereof. Libraries of candidate compounds that can beused in the above methods are commercially available. The candidatecompounds to be screened, can be obtained using any of the numerousapproaches in combinatorial library methods known in the art, including:biological libraries; spatially addressable parallel solid phase orsolution phase libraries; synthetic library methods requiringdeconvolution; the “one-bead one-compound” library method; and syntheticlibrary methods using affinity chromatography selection. The biologicallibrary approach is limited to peptide libraries, while the other fourapproaches are applicable to peptide, non-peptide oligomer, or smallmolecule libraries of compounds (Lam, Anticancer Drug Des., 12:145,1997).

Examples of methods for the synthesis of molecular libraries can befound in the literature, for example in: DeWitt et al., Proc. Natl.Acad. Sci. U.S.A., 90:6909, 1993; Erb et al., Proc. Natl. Acad. Sci.U.S.A., 91:11422, 1994; Zuckermann et al., J. Med. Chem., 37:2678, 1994;Cho et al., Science 261:1303, 1993; Carrell et al., Angew. Chem. Int.Ed. Engl., 33:2059, 1994; Carell et al., Angew. Chem. Int. Ed. Engl.,33:2061, 1994; and Gallop et al., J. Med. Chem., 37:1233, 1994.

Libraries of compounds may be presented in solution (e.g., Houghten,Bio/Techniques, 13:412-421, 1992), or on beads (Lam, Nature, 354:82-84,1991), chips (Fodor, Nature 364:555-556, 1993), bacteria (U.S. Pat. No.5,223,409), spores (U.S. Pat. Nos. 5,571,698; 5,403,484; and 5,223,409),plasmids (Cull et al., Proc. Natl. Acad. Sci. U.S.A., 89:1865-1869,1992) or phage (Scott and Smith, Science, 249:386-390, 1990; Devlin,Science, 249:404-406, 1990; Cwirla et al., Proc. Natl. Acad. Sci.U.S.A., 87:6378-6382, 1990; and Felici, J. Mol. Biol., 222:301-310,1991).

EXAMPLES Example 1 Soluble MANF Expression is Increased During ER Stressin Pancreatic β-Cells

Experiments were performed to determine if expression of soluble MANF isinduced in pancreatic β-cells in response to endoplasmic reticulumstress. These experiments were performed using rodent pancreatic β-celllines (INS-1 832/13 and MIN6), primary mouse and human islets, and twodifferent chemical agents that induce endoplasmic reticulum stress(thapsigargin and tunicamycin). INS-1 832/13 cells were cultured inRPMI-1640 containing 10% fetal bovine serum, penicillin, streptomycin,sodium pyruvate, and 0.1% β-mercaptoethanol. Primary islets wereobtained from Prodo, and plated into 6-well plates precoated withlaminin V produced by 804G cells, and cultured in CMRL mediumsupplemented with fetal bovine serum, non-essential amino acids, sodiumpyruvate, and antibiotics.

Soluble MANF protein was detected in the medium of a cultured ratpancreatic β-cell line (INS-1 832/13) following treatment withthapsigargin (50 nM) (FIG. 1). Elevated levels of MANF mRNA weredetected in the same cell line following treatment with either 5 μMtunicamycin or 20 nM thapsigargin for 24 hours (FIG. 2).

The data from experiments performed using mouse primary islets furthershow that treatment of mouse islets with 0.5 μM thapsigargin for 6 hoursresults in a significant increase in MANF mRNA expression (FIG. 3). Asecond set of experiments were performed using human primary islets fromtwo human donors. These data also show that treatment of human isletswith thapsigargin (0.25 μM) results in a significant increase in MANFmRNA expression (FIG. 4), and the production and release of soluble MANFprotein into the extracellular medium (FIGS. 5 and 6).

Experiments were performed to determine whether soluble MANF protectspancreatic β-cells from endoplasmic reticulum stress. In a first set ofexperiments, MANF expression was knocked down using one of threedifferent siRNA constructs targeting MANF mRNA. Lipofectamine 2000 wasused according to the manufacturer's protocol to perform thetransfections. The data from these experiments show that knockdown ofMANF expression results in increased endoplasmic reticulum stress (asindicated by an increase in BiP mRNA levels) when the cells are treatedfor 24-hours with tunicamycin (2 μM) compared to control cellstransfected with a control siRNA and treated with the same level oftunicamycin (FIG. 7). These data indicate that soluble MANF plays a rolein preventing or decreasing endoplasmic reticulum stress in pancreaticβ-cells.

Additional experiments were performed to determine whether soluble MANFwould decrease or delay endoplasmic reticulum stress-induced apoptosisin pancreatic β-cells treated with an endoplasmic reticulumstress-inducing chemical agent. The data from these experiments showthat treatment of a mouse pancreatic β-cell line (MIN6) with solubleMANF significantly reduced the amount of caspase-3 cleavage observed inthe cells following treatment with tunicamycin (1 μM, 24 hours) (FIG.8). These data indicate that soluble MANF can prevent or delayendoplasmic reticulum stress-induced apoptotic cell death in pancreaticβ-cells.

Example 2 System for Monitoring Redox States in the ER

A new system to monitor the redox state of the ER in a cell wasdeveloped. In this system, the signal sequence of mouse BiP and themammalian ER retrieval signal(KDEL), was appended to the N- andC-terminus of the redox-sensitive green fluorescent protein (GFP),respectively (FIG. 9A). The recombinant protein was named MEROS-GFP(Mammalian Endoplasmic Reticulum-Localized RedOx-Sensitive GFP).Fluorescence microscopy was used to confirm that MEROS-GFP was localizedto the ER (FIG. 9B). MEROS-GFP displayed distinct excitation spectra inthe fully oxidized and reduced species in NSC34 cells, with maxima at394 nm and 473 nm (FIG. 10A). NSC 34 cells were cultured in DMEMcontaining 10% fetal bovine serum, penicillin, and streptomycin.

The emission spectra from the two distinct excitation wavelengths, 508nm and 510 nm, were comparable (FIGS. 10B and 10C). Confocal microscopyanalysis confirmed that fluorescence from 476 nm excitationsignificantly increased, while fluorescence at 405 nm slightlydecreased, in cells treated with the strong reducing agentdithiothreitol (DTT) (FIG. 11).

The ratio between fluorescence from excitation 473 nm versus 394 nmnormalized to wild-type untreated cells is called the MEROS-GFP ratio.The MEROS-GFP ratio was determined using a fluorescent plate reader. Inthese experiments, the INS-1 832/13 cells were plated onto a 96-wellplate at 50,000 cells/well, the cells treated with H₂O₂ or DTT atvarious concentrations for 30 minutes, and the fluorescence atexcitation wavelength 473 nm and emission wavelength 510 nm (for reducedMEROS-GFP) or at excitation wavelength 394 nm and emission wavelength510 nm (for oxidized MEROS-GFP) was measured. The MEROS-GFP ratio wasdetermined after substraction of background signal. The data show thatan oxidizing agent, H₂O₂, did not change the MEROS-GFP ratio-indicatingthat MEROS-GFP is almost 100% oxidized in vivo (FIG. 12). In contrast,DTT treatment increased the MEROS-GFP ratio in a dose-dependent manner(FIG. 12).

Additional experiments were performed to confirm that the MEROS-GFPratio reflected changes in its redox state in vivo. In theseexperiments, the redox state of MEROS-GFP was monitored usingnon-reducing SDS-PAGE in combination with the thiol-alkylating reagent,4-acetamido-4′-maleimidylstilbene-2, 2′-disulfonic acid (AMS). In theseexperiments, INS-1 832/13 cells left untreated or treated with 2 mM DTT,were lysed with 1× SDS-PAGE sample buffer containing 25 mM AMS with orwithout 2-β-mercaptoethanol, boiled at 95° C. for 10 minutes,electrophoresed using SDS-PAGE, and immunoblotted using an anti-GFPantibody. As expected, non-reducing SDS-PAGE of lysates from DTT-treatedcells showed only one slower migrating form of MEROS-GFP, indicatingthat the DTT treatment fully reduced MEROS-GFP in vivo (FIG. 13).

The MEROS-GFP ratio was also monitored in DTT-treated cells at differenttime points. FIG. 14 shows that the ER could be reduced within a fewminutes of treatment of DTT, and return to an oxidized environmentwithin a minute of DTT washout. These results indicate that MEROS-GFPcan be used for real-time, live-monitoring of the redox state within theER of mammalian cells.

Flow cytometry was used to precisely monitor the MEROS-GFP ratio invivo. These data show that treatment of the pancreatic β-cell line,INS-1 832/13, with DTT resulted in a dose dependent increase in theratio of fluorescence from excitation at 488 nm versus 405 nm (FIGS. 15and 16). To further analyze this observation, the median MEROS-GFP ratiowas examined in DTT-treated cells. The data show that DTT treatmentincreased the median MEROS-GFP ratio in a dose-dependent manner (FIG.17). However, H₂O₂ treatment did not change the MEROS-GFP ratio (FIG.18), indicating that MEROS-GFP was almost fully oxidized in the ER atbasal levels. The median MEROS-GFP ratio was also increased by bothexperimental and physiological inducers of ER stress, includingtunicamycin, thapsigargin, brefeldin A, MG 132 (FIGS. 19 and 20),chronic high glucose (FIG. 21), serum depletion, glucose deprivation(FIG. 22), palmitate, human islet amyloid polypeptide (hIAPP), andinflammatory cytokines (FIGS. 23 and 24).

Example 3 Heterogeneity in ER Redox States in ER Stressed Cells

Two distinct cell populations were observed by flow cytometry followingthe treatment of INS-1 832/13 cells with palmitate (a strong ER inducerfor pancreatic βcells): one that could maintain an oxidized ER state,and another that had a highly reduced ER (FIGS. 25 and 26). In order tofurther study these heterogenous populations of cells, the cells thathad a MEROS-GFP ratio of greater than 2 were categorized as “reducedcells.” These two different populations of cells were also observedfollowing treatment with other known ER stress inducers for pancreaticβ-cells, including chronic high glucose (FIG. 27), serum depletion,glucose deprivation (FIG. 28), and human IAPP (FIG. 29). Among thestress inducers, palmitate treatment leads to the greatest increase incell population with highly reduced ER. Interestingly, the unsaturatedfatty acids, oleic and linoleic acid, which have previously been shownto be protective against palmitate-induced cell dysfunction,significantly suppressed the ability of palmitate to create a reduced ER(FIG. 30). These data indicate that ER-stressed cells are heterogenousin their redox state.

Example 4 Activation of the Unfolded Protein Response (UPR) in Cellswith a Reduced ER

Experiments were performed to study the relationship between the UPR andthe heterogeneity of the redox state. In these experiments, both theredox state and the activation levels of the UPR were monitored in thesame cells. To achieve this, a UPR reporter gene encoding the redfluorescent protein, mCherry, driven by the human BiP promoter wasconstructed. The BiP promoter contains three unfolded protein responseelements (UPRE) and has been shown to efficiently reflect the activationlevels of the UPR. This BiP-mCherry reporter plasmid was transfectedinto INS-1 832/13 cells expressing MEROS-GFP, and FACS analysis was usedto monitor the MEROS-GFP ratio and the activation levels of the UPR viaBiP-mCherry in the same cells (FIG. 31). The activation levels ofBiP-mCherry and the MEROS-GFP ratio were monitored following theinduction of ER stress. In these experiments, INS-1 832/13 cellsexpressing MEROS-GFP were plated onto 6-well plates, treated with eachcompound for indicated times, and then harvested by trypsinization.After washing with phosphate buffered saline, cells were resuspended inthe 11 mM glucose-Hanks buffered salt solution. Flow cytometry analyseswere performed with LSRII (BD).

The data show that the cell population with reduced ER (the MEROS-GFPratio >2.0) had higher activation levels of BiP-mCherry as compared tothe cells that could maintain an oxidized ER, signifying activation ofthe UPR in the highly reduced ER cell population (FIGS. 32 and 33).

Additional experiments were performed to confirm these data. In theseexperiments, cells with oxidized ER and highly reduced ER were sorted byFACS following treatment with palmitate (FIGS. 34 and 35), and theexpression of the UPR markers BiP and spliced XBP-1 were measured usingreal-time PCR. In these experiments, the reduced and oxidized cells weresorted by FACS and total RNA was extracted by RNeasy kit (Qiagen).Reverse-transcriptase and quantitative PCR was performed using BioRadiQ5 using SYBR green dye.

The data show that expression levels of BiP and spliced XBP-1 wereincreased in the cells with highly reduced ER as compared to the levelsin the cells with an oxidized ER (FIG. 36). These data were furtherconfirmed by expression profiling in cells with reduced ER and oxidizedER (FIG. 37). These experiments were performed using FACS-sorted INS-1832/13 cells treated with 0.5 mM palmitate for 24 hours. The total RNAwas extracted with an RNAeasy kit (Qiagen). The purified RNA was thenapplied to GeneChip Rat Gene 1.0 ST Array (Affymetrix) according to themanufacturer's protocol. These data indicate that cells harboring highlyreduced ER also have highly activated UPR, possibly as a regulatorymechanism.

Example 5 A Small Molecule Screen for Compounds that Shift ER from aReducing to an Oxidizing Environment

The data described above indicate that chemical compounds and biologicsthat shift the ER towards an oxidizing environment might be effectivefor the treatment of diseases related to ER stress and ER dysfunction.To investigate this possibility, two FDA-approved drugs, pioglitazone(Actos) and tauroursodeoxycholic acid (TUDCA), could affect the ER redoxstate and ameliorate cell death in cellular models of ER diseases.Pioglitazone is approved for treating patients with type 2 diabetes andhas been shown to preserve pancreatic β-cell function in a mouse modelof Wolfram syndrome. Pioglitazone was shown to shift the ER to anoxidizing environment in pancreatic β-cells treated with thapsigargin(FIG. 38, right panel) and protect these cells from cell death (FIG. 38,left panel). Another small molecule, TUDCA, has been used for treatmentof gallstones and biliary cirrhosis and shown to mitigate ER stress inmouse models of diabetes. TUDCA was shown to also shift the ER towardsan oxidizing environment (FIG. 38, right panel) and to protect cellsfrom death under ER stress conditions (FIG. 38, left panel).

The finding that agents shifting the ER towards an oxidizing environmentcan confer protection against ER stress allows for the development of anew screening assay to identify novel small molecule suppressors ofreduced ER using a high-throughput approach. A pilot screen of a1280-compound library (MicroSource), a collection of 1,040 U.S. drugsand 240 international drugs (FIG. 39) was performed. In this experiment,INS-1 832/13 cells stably-expressing MEROS-GFP were seeded (20,000cells/well) in black optical 96-well plates. After 24 hours, 2 μL ofeach compound was added using the TeMo liquid handling robot. Afteranother 24 hours, cells were challenged with 0.2 mM DTT, a strongreducing agent, for 2 hours, and then the MEROS-GFP ratio wascalculated. The average ratio of untreated cells was 0.037 (S.D. =0.003)and that of DTT-treated cells was 0.069 (S.D. =0.006). Positivecompounds were those that could maintain the MEROS-GFP ratio lower than0.05. Using this criterion, 20 positive compounds were identified in thescreen.

A second screen was performed using 0.4 mM palmitate in combination with20 mM glucose to induce ER stress. Between both screens, 9 commonpositive compounds were identified, of which 5 were eliminated due toautofluorescence. To further eliminate false positives, INS-1 832/13cells stably-expressing MEROS-GFP were pretreated with the remaining 4common compounds, challenged with 0.5 mM palmitate for 24 hours, and theMEROS-GFP ratio measured using FACS. This additional step removed twocompounds as false positives. The remaining two compounds were theclinically used agents apomorphine and griseofulvin. Although positivelyidentified in the screening assays, griseofulvin had strong toxiceffects on INS-1 832/13 cells.

Example 6 Apomorphine Shifts the ER Toward an Oxidizing Environment andConfers Protection Against ER Stress

Additional experiments were performed to confirm that apomorphine couldshift the ER from a reducing to an oxidizing environment. In theseexperiments, INS-1 832/13 cells expressing MEROS-GFP were treated withapomorphine for 24 hours, and then challenged with palmitate for 24hours. The data show that apomorphine treatment decreased the populationof cells that had reduced ER (FIG. 40). Cell viability and mitochondrialmembrane potential in INS-1 832/13 cells treated with palmitate wasmeasured using propidium iodide (PI) and MitoProbe (Invitrogen)staining, respectively. Apomorphine decreased the population with lowermitochondrial membrane potential (FIG. 41) and suppressed ERstress-induced cell death (FIG. 42). Apomorphine also protected INS-1832/13 cells from ER stress-mediated cell death induced by a strong ERstress inducer, thapsigargin (FIG. 43). Collectively, these data showthat apomorphine shifts the ER toward an oxidizing environment andconfers protection against ER stress.

Example 7 Small Molecules Shifting the ER Towards an OxidizingEnvironment can Alleviate the Pathology of Cellular Models of ER Stress

The data above show that apomorphine and pioglitazone have the abilityto shift the ER towards an oxidizing environment and conferredprotection against ER stress. Additional experiments were performed todetermine whether apomorphine and pioglitazone can protect human isletsfrom ER stress-mediated cell death. The data show that both apomorphineand pioglitazone could protect human islets from thapsigargin-mediatedcell death (FIG. 44, left panel).

Additional experiments were performed using INS-1 832/13-deriveddoxycycline-inducible WFS1 knockdown cells, a cellular model of Wolframsyndrome. This model was used to test whether apomorphine andpioglitazone could prevent cell death. As previously reported,shRNA-mediated WFS1 knockdown resulted in cell death, accompanied bycleavage of caspase-3 (Riggs et al., Diabetologia 48:2313-2321, 2005).In this model, both apomorphine and pioglitazone suppressed cleavage ofcaspase 3 and cleavage of a caspase 3 substrate, poly(ADP)-ribosylatingenzyme (PARP), and could protect WFS1-knockdown β-cells from cell death(FIG. 44, right panel). Taken together, these data show that smallmolecules that shift the ER towards an oxidizing environment canalleviate pathology of cellular models of ER diseases.

Example 8 Soluble MANF Protects Pancreatic β-Cells from ER Stress and ERStress-Induced Apoptotic Cell Death

Further experiments were performed to determine whether soluble MANF canprevent fluctuations in the redox environment in the endoplasmicreticulum of pancreatic β-cells upon exposure to an agent that inducesendoplasmic reticulum stress. Experiments were performed using INS-1832/13 cells (a pancreatic β-cell line) transfected with a lentivirusvector expressing MEROS-GFP. The cells were cultured in 11 mM or 25 mMglucose, and either left untreated or treated with 0.5 μg/mL solubleMANF. The cells were then analyzed using FACS analysis using anexcitation spectrum between 460-495 nm and an emission spectrum ofbetween 520-570 nm (FITC-A optical filter) which allows for the specificdetection of fluorescent emission from reduced EroGFP in the transfectedcells. The data show that treatment with soluble MANF results in adecrease in the number of cells containing a detectable level of reducedMEROS-GFP (FIG. 45; lower right panel vs. lower left panel). Consistentwith the data above, these data show that treatment of pancreaticβ-cells with soluble MANF can shift the ER towards an oxidizingenvironment and may be used to treat or prevent the development of apancreatic 13 cell disorder in a subject.

Other Embodiments

It is to be understood that while the invention has been described inconjunction with the detailed description thereof, the foregoingdescription is intended to illustrate and not limit the scope of theinvention, which is defined by the scope of the appended claims. Otheraspects, advantages, and modifications are within the scope of thefollowing claims.

The invention claimed is:
 1. A method of diagnosing a pancreatic β-celldisorder in a subject, and treating the pancreatic β-cell disorder inthe subject, the method comprising: determining a level of solublemesencephalic astrocyte-derived neurotrophic factor (MANF) in abiological sample from a subject; comparing the level of soluble MANF inthe biological sample to a reference level of soluble MANF; identifyinga subject as having an elevated level of soluble MANF in the biologicalsample as compared to the reference level; and administering to theidentified subject a treatment comprising an effective amount of MANF.2. The method of claim 1, further comprising monitoring pancreaticβ-cell function or pancreatic β-cell mass in a subject by a methodcomprising: determining a level of soluble mesencephalicastrocyte-derived neurotrophic factor (MANF) in a biological sample fromthe subject at a first time point; determining a level of soluble MANFin a biological sample from the subject at a second time point; andcomparing the level of soluble MANF in the biological sample at thesecond time point to the level of soluble MANF in the biological sampleat the first time point, wherein an elevated level of soluble MANF inthe biological sample at the second time point compared to the level ofsoluble MANF in the biological sample at the first time point indicatesa decrease in pancreatic β-cell function or a decrease in pancreaticβ-cell mass in the subject, and a decrease or no significant change inthe level of soluble MANF in the biological sample at the second timepoint compared to the level of soluble MANF in the biological sample atthe first time point indicates no change or an increase in pancreaticβ-cell function, or no change or an increase in pancreatic β-cell massin the subject.
 3. The method of claim 1, comprising administering tothe subject a treatment comprising an effective amount of MANFcomprising a sequence that is at least 80% identical to SEQ ID NO:
 2. 4.The method of claim 3, further comprising monitoring the efficacy of thetreatment of a pancreatic β-cell disorder in the subject, the methodcomprising: determining a level of soluble mesencephalicastrocyte-derived neurotrophic factor (MANF) in a biological sample fromthe subject at a first time point; determining a level of soluble MANFin a biological sample from the subject at a second time point; andcomparing the level of soluble MANF in the biological sample at thesecond time point to the level of soluble MANF in the biological sampleat the first time point, wherein (i) the first time point is prior totreatment and the second time point is any time point following theinitiation of treatment, or (ii) the first time point is following theinitiation of treatment and the second time point is at a later timepoint during or after treatment; and a decreased level of soluble MANFin the biological sample at the second time point compared to the levelof soluble MANF in the biological sample at the first time pointindicates that the treatment was effective in the subject.
 5. A methodof selecting a subject for treatment of a pancreatic β-cell disorder,the method comprising: determining a level of soluble mesencephalicastrocyte-derived neurotrophic factor (MANF) in a biological sample froma subject; comparing the level of soluble MANF in the biological sampleto a reference level of soluble MANF; selecting a subject that has anelevated level of soluble MANF in the biological sample as compared tothe reference level, and administering to the selected subject atreatment of a pancreatic β-cell disorder.
 6. The method of claim 5,wherein the pancreatic β-cell disorder is selected from the groupconsisting of: type 1 diabetes, type 2 diabetes, and Wolfram syndrome.7. The method of claim 5, wherein the reference level is a thresholdlevel of soluble MANF.
 8. The method of claim 5, wherein the referencelevel is a level of soluble MANF in a healthy subject.
 9. The method ofclaim 5, wherein the subject is a human.